# Synendo > Apps for creatives, respectful of your data Synendo builds privacy-first tools for creative professionals. Its apps run on your own hardware — on-device on your Mac, or self-hosted on your own Raspberry Pi — with no cloud uploads, no data leaving your control, and one-time purchases or open source instead of subscriptions. - **Website:** https://www.synendo.com/ ## Products ### [VisionTagger](https://www.synendo.com/visiontagger/) > Never tag photos manually again. VisionTagger is a macOS app that uses on-device AI to generate titles, descriptions, keywords, and structured metadata for your images. Pay once, process unlimited images — no cloud uploads, no subscriptions, no per-image fees. Export XMP sidecars for Lightroom and Capture One, JSON/CSV for web pipelines, Finder tags, or write back to Photos. Everything runs locally on your Mac. - **Platform:** Requires Apple Silicon Mac with macOS 26 - **Price:** €24.99 - **Markdown:** https://www.synendo.com/visiontagger.md ### [GD Studio](https://www.synendo.com/gdstudio/) > Generative art, made to plot. GD Studio (Generative Drawing Studio) is a macOS app for designing generative artwork for pen plotters. Choose from 50 patterns across 8 families, shape them with live controls, layer in text and imported SVG, turn a photo into plottable line art, and export plotter-ready SVG, PDF, or print — or plot straight from the canvas with Plotter Hub. Every pattern is built from continuous strokes, so the canvas is an honest preview of the pen's path. - **Platform:** Requires macOS 15 or later - **Price:** €24.99 - **Markdown:** https://www.synendo.com/gdstudio.md ### [Plotter Hub](https://www.synendo.com/plotterhub/) > Plot over the network. Plotter Hub is a self-hosted plot server for AxiDraw-class pen plotters, running on a Raspberry Pi. Drag and drop an SVG in your browser and the Pi drives the plotter locally via the official AxiDraw Python API — with layer-by-layer plotting, pen-change pauses, paper-size presets, optional vpype path optimization, a live pen-position cursor, and physical pause-button support. Free and open source under the MIT License. - **Platform:** Requires Raspberry Pi OS - **Price:** Free, open source - **Markdown:** https://www.synendo.com/plotterhub.md --- ## Other languages - de: https://www.synendo.com/de/ - ja: https://www.synendo.com/ja/ - fr: https://www.synendo.com/fr/ - zh-Hans: https://www.synendo.com/zh-Hans/ - es: https://www.synendo.com/es/ - it: https://www.synendo.com/it/ - nl: https://www.synendo.com/nl/ - pt: https://www.synendo.com/pt/ - ko: https://www.synendo.com/ko/ --- # VisionTagger > Never tag photos manually again. VisionTagger uses on-device AI to generate titles, descriptions, keywords, and more for your images — in bulk, with no uploads and no per-image fees. VisionTagger is a macOS app that uses on-device AI to generate titles, descriptions, keywords, and structured metadata for your images. Pay once, process unlimited images — no cloud uploads, no subscriptions, no per-image fees. Export XMP sidecars for Lightroom and Capture One, JSON/CSV for web pipelines, Finder tags, or write back to Photos. Everything runs locally on your Mac. - **Developer:** Synendo - **Website:** https://www.synendo.com/visiontagger/ - **Requirements:** Requires Apple Silicon Mac with macOS 26 - **Price:** €24.99 — VAT included (except US & CA) - **Download Free Trial:** https://www.synendo.com/apps/visiontagger/VisionTagger.dmg - **Buy VisionTagger:** https://synendo.onfastspring.com/visiontaggerv1 ## Who is VisionTagger for? - **[Photographers with thousands of untagged photos](https://www.synendo.com/visiontagger/photo-metadata)** — batch-process entire shoots and export XMP sidecars with keywords, captions, and more — ready to import into Lightroom, Capture One, or Photo Mechanic. - **[Anyone who can never find that one photo](https://www.synendo.com/visiontagger/photo-metadata)** — generate searchable titles, descriptions, and Finder tags so every image in your library is findable — today and years from now. - **[Web teams who need alt text at scale](https://www.synendo.com/visiontagger/alt-text)** — generate accurate, consistent alt text for hundreds of website images — improving accessibility and SEO without uploading to third-party services. - **Designers searching across project assets** — tag images by mood, style, subject, and usage to make your asset library instantly searchable. - **Researchers and archivists preserving collections** — create structured, consistent metadata for datasets, records, and long-term digital preservation. ## Features ### Smarter results with context you already have Tell the AI what it’s looking at and the results get dramatically better. Add a Context Hint like “product photos for a vintage furniture store,” turn on GPS Location to include place names from embedded coordinates, or pass along camera and editorial metadata already in your files. Each source is optional and feeds directly into the prompt — so the AI doesn’t have to guess. ### Generate exactly the metadata you need Start with the fields most people need — Title, Description, and Keywords — then go further with Content & Style, Safety & Compliance, or add entirely custom sections with your own fields and prompts. Need output in another language? VisionTagger can automatically translate generated metadata using macOS built-in Translation. The result is structured, consistent metadata across thousands of photos. ### Fits right into your workflow For XMP sidecars and embedded metadata, VisionTagger integrates with [ExifTool](https://exiftool.org) — an industry-standard, widely trusted utility. Your metadata will appear in apps like Adobe Lightroom, Bridge, Capture One, Photo Mechanic, and any other software that reads XMP. Write back to your Photos Library, export JSON, CSV or TXT per image, or generate a single file for an entire run. Add Finder tags for fast organization in macOS. Select multiple outputs at once and configure them together — so one generation pass can feed every destination you use. ### Automate it and forget about it Two Shortcuts actions — one for files in Finder, one for your Photos Library — let you run the full process in the background without opening the app. Set up a folder automation, a Finder Quick Action, or trigger it from the command line. Use the app’s current settings or supply a saved preset for reproducible results every time. ## How it works 1. **Source** — Choose where your images are stored — folders on your Mac or your Photos Library. 2. **Select** — Pick exactly what you want to process. Browse your selection in a grid or table view, add more images via the add button, or drag and drop files into the app to build a batch. 3. **Content** — Pick an AI model (download one in-app with a click) and choose what metadata to generate: titles, descriptions, keywords, style tags, safety ratings, or your own custom fields. 4. **Generate** — Watch results appear in real time. VisionTagger processes images locally and streams generated metadata into a scrolling list as soon as each item is ready, so you can review and edit outputs while the batch continues. 5. **Format** — Choose where metadata goes: XMP sidecars for your photo catalog, JSON or CSV for your website pipeline, Finder tags, or write back to Photos. Select multiple outputs at once. 6. **Publish** — Confirm before anything is written. Review a clear summary of all actions that will be executed, including warnings when existing files or metadata may be overwritten — then publish to apply your selected outputs with confidence. [Watch demo on YouTube](https://youtu.be/AIZ3BQHsUkY) ## One-Time Purchase €24.99 ~~€29.99~~ (Special offer) - Free trial: 100 images, no time limit - Single payment. No recurring fees. - Single user. Multiple Macs. VAT included (except US & CA). Secure payment via FastSpring ## VisionTagger FAQ ### Getting started **How does the free trial work?** The free trial lets you process up to 100 images at no cost, with no time limit. You can explore the full workflow—model selection, built-in sections, custom fields, and export options—before purchasing. ### Images & metadata **Which image formats and sources are supported?** VisionTagger supports common image formats such as JPEG, PNG, TIFF, HEIC, and WebP, as well as various RAW formats including DNG. You can select images from folders on your Mac or directly from your Photos Library. **Can I adjust the description verbosity?** Yes. You can choose between three levels: Brief for a single concise sentence suitable for alt text, Standard for two sentences with context ideal for captions, or Detailed for a comprehensive description. **Can I control which keywords are generated?** Yes. You can set a maximum number of keywords so the model generates up to that many keywords per image. You can also define keywords to always include at the start or end of the list, and specify keywords to exclude. After generation, you can manually reorder, edit, add, or delete keywords for each individual image before exporting. **Can I define custom metadata fields?** Yes. In addition to built-in sections (Title, Description, Keywords, Content & Style, Safety & Compliance), [you can create custom sections and add your own fields](https://youtu.be/S2oEM6LTHVQ). Each field supports a data type (Boolean, Text, or List of Texts) and its own prompt, so you can tailor exactly what the model extracts. ### Exports & integrations **Can VisionTagger write back to my Photos Library?** Yes. VisionTagger can write metadata back to your Photos Library when you choose that output option. You will always see a publish summary before anything is written. **What outputs can VisionTagger create?** VisionTagger can export JSON, CSV or TXT per image, or a single JSON/CSV/TXT file for an entire batch. It can also apply Finder tags. For XMP sidecars and embedding metadata into image files, VisionTagger integrates with [ExifTool](https://exiftool.org) (installed separately). **Can VisionTagger output metadata in languages other than English?** Yes. VisionTagger always generates metadata in English for optimal AI model quality. When you select a different output language in Settings, the generated metadata is automatically translated using macOS built-in Translation. Supported languages include Arabic, Chinese, Dutch, French, German, Hindi, Indonesian, Italian, Japanese, Korean, Polish, Portuguese, Russian, Spanish, Thai, Turkish, Ukrainian, and Vietnamese. Language packs must be downloaded in System Settings before translation is available. **Do I need to install ExifTool?** [ExifTool](https://exiftool.org) is only required for XMP sidecars and embedding metadata into image files. If you only export JSON/CSV/TXT or apply Finder tags, you do not need ExifTool. **Will VisionTagger overwrite existing files or metadata?** VisionTagger shows a publish summary before writing any outputs and warns you if existing files may be overwritten. You can review the actions and confirm before anything is saved. ### Requirements **Do I need to configure anything technical?** No. Download a model with one click and start processing. VisionTagger ships with sensible defaults. If you want more control, you can adjust parameters like output length in Settings — but most users never need to. **Does VisionTagger require an internet connection?** VisionTagger runs locally and does not upload your images or generated metadata. An internet connection is only needed to download models in-app and to check for and download app updates. **How fast is it, and what Mac do I need?** VisionTagger requires Apple Silicon (M1 or later) and runs on macOS Tahoe 26.0 or later. 16 GB of RAM is the minimum; for larger models, 32 GB or more is recommended. Speed depends on your Mac, the selected model, image resolution, and your chosen metadata fields. Smaller models typically run faster; larger models can produce higher-quality results. **How much disk space do models use?** Model downloads are stored locally. Plan for roughly 4–8 GB per model (varies by model). ### Automation **Can I automate VisionTagger?** Yes. VisionTagger integrates with Apple Shortcuts through two actions: Generate Image Metadata (for files in Finder) and Generate Photo Metadata (for your Photos Library). Both run the full pipeline in the background and export results to your configured destinations. You can use them in the Shortcuts app, Finder Quick Actions, folder automations, the command line, and AppleScript. Optionally supply a settings preset exported from the app for reproducible automation. ### AI models **Can VisionTagger recognize specific people or faces?** No. VisionTagger uses general-purpose pretrained vision models, so it can describe that a person is present and note visible attributes, but it cannot identify or tag specific individuals by name. The models are not trained for facial recognition, and there is no way to teach them to recognize particular people. **Which vision models are included?** VisionTagger includes seven preconfigured vision models: Qwen3-VL 8B Instruct, Qwen3-VL 30B-A3B Instruct, Qwen3-VL 32B Instruct, Qwen2.5-VL 7B Instruct, Gemma 3 4B IT, InternVL3 8B Instruct, and Pixtral 12B. Smaller models generally run faster, while larger models may produce higher-detail output but require more memory, depending on your Mac and chosen settings. Use the trial to compare models and tweak parameters until the results match your workflow and preferred level of detail. **Can I use my own models?** Yes. If you have a GGUF-compatible vision model and its matching projector file (also GGUF), you can [link them](https://youtu.be/V21D3kcudQc) in VisionTagger and use them like the built-in options. You are responsible for ensuring your use of third-party models complies with their licenses and terms. **Can I tune the model parameters?** Yes. In Settings you can adjust generation parameters such as temperature, max tokens, context length, top-P, and top-K using sliders. This helps you balance creativity versus consistency and control output length and detail. ### Privacy **How does VisionTagger compare to cloud keywording services?** Most cloud keywording services charge per image and require uploading your photos to their servers. VisionTagger is a one-time purchase with no per-image fees — process as many images as you want. Your photos never leave your Mac, and metadata is written directly to XMP sidecars and your files instead of a CSV export you have to import manually. **Does the GPS Location feature send my data anywhere?** GPS coordinates embedded in your images are sent anonymously to Apple Maps to look up place names. Only the coordinates are sent — Apple does not collect personal data associated with your Maps usage. The GPS Location feature is disabled by default. **Does the translation feature send data to Apple?** By default, macOS may use Apple’s online translation services for improved accuracy. To ensure all translation happens entirely on your Mac with no data leaving the device, enable “On-Device Mode” in System Settings > Translation. **Does VisionTagger collect any usage data or analytics?** No. VisionTagger does not include analytics or telemetry, and it does not upload your data. Licensing activation and update checks involve network requests as needed for those functions. --- # GD Studio > Generative art, made to plot. GD Studio lets you design generative artwork for pen plotters. Pick a pattern, shape it with live controls, add text or SVG elements, and export a plotter-ready file. GD Studio (Generative Drawing Studio) is a macOS app for designing generative artwork for pen plotters. Choose from 50 patterns across 8 families, shape them with live controls, layer in text and imported SVG, turn a photo into plottable line art, and export plotter-ready SVG, PDF, or print — or plot straight from the canvas with Plotter Hub. Every pattern is built from continuous strokes, so the canvas is an honest preview of the pen's path. - **Developer:** Synendo - **Website:** https://www.synendo.com/gdstudio/ - **Requirements:** Requires macOS 15 or later - **Price:** €24.99 — VAT included (except US & CA) - **Download Free Trial:** https://www.synendo.com/apps/gdstudio/GDStudio.dmg - **Buy GD Studio:** https://synendo.onfastspring.com/gdstudiov1 ## Who is GD Studio for? GD Studio — short for Generative Drawing Studio — turns mathematical patterns into designs your pen plotter can draw, without writing a line of code. If you own a plotter, or you're simply drawn to the look of machine-drawn line art, it's built for you. - **Generative artists and creative coders** — explore parametric patterns visually, with live feedback, instead of recompiling a sketch to see a change. - **Designers and makers** — produce line-art posters, cards, logos, and lettering as clean vector strokes. - **Educators and math enthusiasts** — see curves, tilings, L-systems, and packings come to life and reshape as you change a single parameter. - **Plotter-curious newcomers** — start from a curated preset and tweak; no setup, no scripting, just continuous strokes that are ready to draw. ## Features ### Dozens of patterns, endless variations Explore 50 patterns across 8 families, from classic curves like Trochoids and Harmonographs to tilings, packings, generative systems, mazes, flow fields, and differential growth. Start from curated presets, then make each design your own: adjust its parameters, change how it is drawn, apply stroke, fill, line-style, and repeat modifiers, split it across colors, or combine multiple patterns in layered compositions. No pattern is limited to a single image. Each one is a flexible system with effectively endless variations. And because every design is built from continuous strokes, the canvas gives you a precise preview of the pen’s path: what you see is what the pen draws. ### Layers, pens, and multi-pen plotting Build each drawing as a stack of layers, with independent control over pen color, stroke width, dash, transform, and render style. Restyle any line with wobble, hatch, stipple, nested outlines, and more using Line, Fill, and Repeat modifiers. Assign each pen to its own layer, or split a single pattern across several pens by path length, tile orientation, spiral arm, contour level, and other pattern-specific properties. Each layer exports as its own labeled SVG group, making it easy for plotter tools to guide pen changes between groups. ### More than patterns: map, 3D model, image, text, SVG, and calibration layers A layer doesn't have to be a pattern. Search for a place and a Map layer draws it as plottable line art — street-level detail for a city, or coastlines and borders for a country, continent, or the whole world, with every feature its own toggle, your own GPX routes drawn on top, and a split by feature for multi-pen plots. Import an OBJ, STL, or PLY mesh and a 3D Model layer draws it as plottable line art — aim the camera anywhere around the object, choose how much of the geometry the pen sees, fill the surface with engraving-inspired shading, and split the result across pens for multi-pen plots. Drop in a photo and an Image layer redraws it as plottable line art — rebuilt from continuous pen strokes and single pen-taps, never a flat ink fill, with eight styles from a delicate stipple to flowing hatch to topographic contour to ASCII, plus an optional color split for multi-pen plots. Add text rendered as real plotter strokes (single-stroke and outline fonts, plus your own custom SVG fonts), import an SVG file to bring existing line art into your design, or drop in a calibration layer — a crosshair for pen registration. Imported SVG and text become regular layers: give them any pen, restyle their lines with the same Line, Fill, and Repeat options, mask them, and transform them like anything else. ### From canvas to pen on paper Export to SVG (Inkscape / axicli layer-group convention), PDF, or print directly — each pen layer is written as its own labeled group, ready for any SVG-capable plotter workflow. Or skip the file step entirely and plot straight from GD Studio with [Plotter Hub](https://www.synendo.com/plotterhub/): a free, open-source app you can install on a Raspberry Pi Zero 2 W or 3B+ to run an AxiDraw-compatible plotter over WiFi instead of USB. Plotter Hub optimizes the SVG before plotting and automatically pauses between layers so you can change pens for each color. ## How it works 1. **Pick a pattern** — Open the welcome window and choose from the Pattern Browser, or start with your most recently used pattern. 2. **Tune it live** — Adjust parameters in the Inspector and watch the canvas redraw instantly. Switch between Design and Formula mode for as much control as you want. 3. **Layer and style** — Add pattern, text, SVG, or calibration layers. Give each its own pen and render style; reorder, hide, and duplicate freely. 4. **Set the page** — Choose paper size, orientation, and margins so the drawing fits your plotter bed. 5. **Export and plot** — Save an SVG (one group per pen), a PDF, print, or send it to Plotter Hub. Load it in your plotter software and draw. ## Made with GD Studio Anything can become a line drawing. Each one is a preview from GD Studio, ready to draw on a pen plotter. Click any thumbnail to view it full screen. Flow Field, Contour Field, Maze, Moiré, Tessellation, Strange Attractor, Harmonograph, Multi Twisted, Epicycles, Superformula, Disordered Grid, Tile Weave, Field Grid, Doctor's Prescription + Subdivision, Sparkle, Vortex, Quasicrystal, Wireframe, Hyperbolic Tiling, Map of Rotterdam, The Netherlands with GPX route of the Marathon, Map of Paris, France, Map of Rome, Italy, 3D model with hatch shading, cast and ground shadows, 3D model with hachures shading, 3D model with bands shading, Ridgeline, Rose Curve, Geometric Packing, L-System, Trochoid, … Map data © [OpenStreetMap](https://www.openstreetmap.org/copyright) contributors, available under the [Open Database License](https://opendatacommons.org/licenses/odbl/). Country, continent, and world cartography from [Natural Earth](https://www.naturalearthdata.com/) (public domain). ## One-Time Purchase €24.99 - Free trial, no time limit. Save designs for all 50 patterns, and export, print, or plot Trochoid designs for free. A license unlocks these options for every pattern. - Single payment. No recurring fees. - Single user, multiple Macs. One license covers all the Macs you use. VAT included (except US & CA). Secure payment via FastSpring ## GD Studio FAQ ### Getting Started **What's in the free trial?** The full app with no time limit. You can open and explore all 50 patterns and tools, and save documents for every pattern. Exporting is available for Trochoid-only documents in trial mode; a license unlocks export for every pattern. ### Patterns & Design **How many patterns are there?** 50 patterns, grouped into 8 families: Curves, Shapes, Points, Multi-line, Tilings, Grids & Packing, Generative Systems, and Simulation. Many patterns also include several built-in Types — each a distinctly different design — multiplying the number of variations several times over. Each pattern ships with curated presets, and fine-grained sliders make the practical variety effectively unlimited. **What's the difference between Design mode and Formula mode?** Design mode gives you high-level controls; Formula mode exposes the underlying mathematical parameters for full control. Simpler patterns show a single set of controls. **Can I randomize or start from a preset?** Yes — every pattern includes curated presets, plus shuffle and reset controls. ### Plotters & Export **Which plotters does GD Studio work with?** Any plotter that accepts SVG. GD Studio exports one labeled group per layer (Inkscape / axicli convention), so axicli, vpype, and Inkscape's plotter extensions can route each layer to its own pen. AxiDraw-class plotters are also supported directly via Plotter Hub. **How do I assign different pens to different parts of a drawing?** Put each pen's content on its own layer — each layer carries its own pen color, stroke width, and dash, and exports as a separate group. To split one pattern across pens, use the Split section of the Pattern tab (by path length, tile orientation, spiral arm, contour level, and more). **What can I export?** SVG, PDF, and direct printing, plus sending straight to a plotter over your local network with Plotter Hub. **Why does my exported SVG look different from the canvas?** Hidden layers are excluded, the page background isn't plotted (it's written as a CSS background that viewers show but plotters ignore — PDF export bakes it in), and the viewport is the drawable area, so anything outside the margins is clipped. ### Maps **Can I draw a map?** Yes. Add a Map layer and pick a scale: search for a city or area to get street-level detail, or choose a country, continent, or the whole world. Every feature is an independent toggle — motorways down to footpaths, railways, rivers, coastline, water, parks, buildings, and boundaries — so you compose exactly the map you want. **Where does the map data come from?** Street-level detail comes from OpenStreetMap (© OpenStreetMap contributors, ODbL); country, continent, and world scales use Natural Earth's public-domain cartography. A first fetch needs an internet connection, and because OpenStreetMap's Overpass service is a free public one, very large areas can take a while. The geometry is then stored inside your document, so a saved map reopens offline and plots identically every time — it's captured, not re-fetched. **Can I put my own route on a map?** Yes — import GPX tracks (a run, a ride, a race route) and they're drawn on top of the map. Import several at once, either merged into one layer or split into one layer per route. **Can I plot a map in multiple colors?** Yes — Split by Map Feature puts each feature class (roads, water, parks…) or each GPX route on its own layer with its own pen, ready for a multi-pen plot. Each layer starts from a cartographic default — water, for example, in blue with a parallel-line fill — and every pen, color, and fill is yours to change from there. Closed areas are hatched rather than flooded, since a pen can't fill. **Can I label the streets?** Yes — street and area names can be turned into editable Text layers, grouped by category. Each label becomes its own text item you can move, resize, or rename on the canvas. ### 3D Models **Can I plot a 3D model?** Yes. Add a 3D Model layer and import an OBJ, STL, or PLY mesh — or start a whole document from a model. GD Studio turns the mesh into pen strokes rather than a shaded render, so the canvas shows exactly what the pen will draw. The model is embedded in the document, so a saved file reopens and plots on any machine without the original asset. If a file uses a different up-axis convention, an override stands it upright, and Replace swaps in a different mesh while keeping the layer's position, size, and all its settings. Large meshes parse in the background, so you'll see a brief loading badge before the drawing appears. **Can I choose the camera angle and projection?** Yes — azimuth, elevation, and roll aim the camera anywhere on the sphere around the object. Four projections are available: Orthographic for a measurable technical view, Isometric at a fixed 30°, Oblique for a true front face with sheared depth (adjustable angle and depth scale, so cabinet and cavalier are both covered), and Perspective with an adjustable focal length. In Perspective, lens shift X/Y moves the camera eye sideways or vertically without rotating it — true two-point architectural perspective that keeps vertical edges vertical. **Which lines of a 3D model does GD Studio draw?** Hidden-line removal: surfaces occlude whatever sits behind them, so you get a solid object rather than a see-through wireframe. You can switch it off for an x-ray look. A mesh detail slider then sets how much of the geometry is drawn — from just the essentials (silhouette, open edges, and sharp feature edges) through progressively flatter folds, up to the full triangle wireframe. **What shading styles are there for 3D models?** Eight, each filling the surface with descriptive strokes instead of a flat fill. Hatch is parallel tonal hatching from a light source; Engraving cuts tonal lines along the model's own axes to wrap the form; Copperplate follows the surface's natural curvature, with a second cross-hatch family filling the shadows for a true engraved gradient; Contours are topographic slice lines, with an optional cross-axis second set; Helix winds that same slicing into one continuous spiral for a lathe-turned look; Bands draws isophotes, or lines of equal illumination; Hachures are cartographic slope hachures, denser on steep faces; and Rim echoes the visible silhouette with offset lines, dense where the surface turns away. Light-driven styles expose light direction and height, and all of them offer spacing in millimeters on paper, density, level count, and smoothing. Three overlay modifiers can be layered on top: depth cue for atmospheric fade, cast shadows for self-shadowing, and a hatched ground shadow on an imaginary floor. **Can I cut a model open?** Yes, and the cut applies to edges, shading, and shadows alike. Cross-Section keeps one half and hatches the exposed cut face, with axis, offset to slide the plane end to end, and flip controls. Slices cuts the whole model into equal slabs fanned out along an axis — set the slice count and the spacing, where zero reassembles it back into a solid — and each slab casts its own shadow. Section fill density and two tilt controls let you skew the cut plane off its axis for arbitrary oblique cuts across all three axes. **Can I plot a 3D model in multiple colors?** Yes — split the model into ordinary pen layers by shading (line work versus shading and shadows), detail (silhouette versus fine feature and mesh lines), hidden lines (their own layer, so you can dash them), depth (front-to-back bands), tone (hatching tones across pens), or slice (each slab to its own layer). After the split the model layer is replaced by regular layers, so you can recolor, restyle, or delete any of them like anything else in the document. ### Images **Can I turn a photo into line art?** Yes. Add an Image layer, drop in a photo (from a file or your Photos library), and pick a conversion style. GD Studio reads the picture's light and dark and rebuilds it from continuous pen strokes and single pen-taps — never a flat ink fill — so the preview matches exactly what the pen draws. Brightness and Contrast sliders shape how the subject reads. Eight styles are available: Stipple, Halftone, Hatch, Contour, Outline, Sketch, Squiggle, and ASCII. **Can I make a multi-color plot from a photo?** Yes — a color split separates the photo into one pen layer per color (faithful Natural, punchy Vivid, or Tonal light-to-dark), so you can swap pens and build up a true multi-color plot. It works with every style. ### Text, SVG & Calibration **Can I add text?** Yes — text is rendered as true plotter strokes, using single-stroke and outline fonts. **Can I use my own fonts?** Yes — add your own custom SVG fonts in Settings and use them in any text layer. **Can I import my own SVG files?** Yes. Add an SVG layer and its lines become the layer's path; you can then restyle those lines with any pen and render style, mask them, or transform them like any other layer. **What's the calibration layer for?** A crosshair for pen registration and plotter calibration. ### Settings & Defaults **Can I change the measurement unit?** Yes — choose millimeters, centimeters, or inches in Settings. Every length input across the app follows your choice. It's a display preference only; documents always store dimensions in millimeters, so switching units never changes how a saved drawing measures on paper. **Can I set my own defaults?** Yes. In Settings you can manage the paper-size list — including adding your own custom sizes — and set the defaults a new document inherits: paper size, orientation, background color, and margins. You can do the same for stroke defaults (line width) and for fonts, including importing custom SVG fonts and choosing the default font and height. **Can I control the output resolution?** Yes. A render-resolution setting controls how closely each curve is followed when it's flattened into plotter segments — from ultra-fine (0.025 mm) for tiny details to draft (0.5 mm) for quick proofs. Lower values give smoother strokes at the cost of larger files and slower exports. ### Privacy **Does GD Studio send my work anywhere?** No. It runs entirely on your Mac. The only network traffic is opt-in: sending to a Plotter Hub server you configured (usually a Raspberry Pi on your own network), fetching map data if you add a Map layer (the area you ask for goes to the public OpenStreetMap and Natural Earth services — you can point this at your own map servers instead), and, if enabled, checking for app updates. Documents, layer content, and pattern parameters never leave your machine. --- # Plotter Hub > Plot over the network. Plotter Hub turns a Raspberry Pi into a networked plot server for your AxiDraw-compatible pen plotter. Submit SVGs from your computer, then let the Pi handle the plot locally from start to finish. Plotter Hub is a self-hosted plot server for AxiDraw-class pen plotters, running on a Raspberry Pi. Drag and drop an SVG in your browser and the Pi drives the plotter locally via the official AxiDraw Python API — with layer-by-layer plotting, pen-change pauses, paper-size presets, optional vpype path optimization, a live pen-position cursor, and physical pause-button support. Free and open source under the MIT License. - **Developer:** Synendo - **Website:** https://www.synendo.com/plotterhub/ - **Requirements:** Requires Raspberry Pi OS - **View on GitHub:** https://github.com/Synendo/PlotterHub ## A small server for your pen plotter Plotter Hub is for [AxiDraw](https://wiki.evilmadscientist.com/AxiDraw)-class plotters that should not need a computer plugged in for every job. Connect the plotter to a Raspberry Pi once, then submit plots from any device on your local network. Drag in an Inkscape-layered SVG and Plotter Hub plots it layer by layer — or send work through its HTTP API. That API is how [GD Studio](https://www.synendo.com/gdstudio/), Synendo's generative drawing app for Mac, plots straight from the canvas to your pen plotter. ## Features Plotter Hub gives you the controls you need for everyday SVG plotting without turning the page into a control panel. - Drag-and-drop SVG upload - Inkscape layer selection - Pause between layers for pen changes - Paper presets, orientation, margins, and fit-to-page - Pen-up and pen-down speed controls - Optional [vpype](https://vpype.readthedocs.io/en/latest/) optimization - Live progress, time estimate, and pen-position preview - Pause, resume, cancel, and physical pause-button support - Runs as a background service — starts on boot - One-click in-app updates - HTTP API for companion apps and scripts **Thanks to Evil Mad Scientist.** Plotter Hub is built on their wonderful open-source [AxiDraw Python API](https://axidraw.com/doc/py_api/) (GPL-2.0), which drives the plotter under the hood. Plotter Hub itself is free and open source under the MIT License. ## Requirements You need: - Raspberry Pi Zero 2 W, 3B+, or newer - Raspberry Pi OS Bookworm or Trixie — Lite (no desktop environment) recommended - An AxiDraw-class USB plotter - A trusted local network A Raspberry Pi Zero 2 W works well as an always-on plot server. A Raspberry Pi 3B+ gives snappier previews and setup. A Pi 4 or 5 is usually unnecessary if Plotter Hub is the only thing running. A clean install is easiest with [Raspberry Pi Imager](https://www.raspberrypi.com/software/). ## How it works 1. **Install on your Pi** — SSH into your Raspberry Pi, clone the repo, and run ./install.sh. It sets up a virtual environment, installs the AxiDraw API and vpype, registers Plotter Hub as a systemd service, and prints the URL to open when it is done. SSH to your Raspberry Pi ``` % ssh plotter@plotterhub.local ``` Update the package index and install git ``` plotter@plotterhub:~ sudo apt update && sudo apt install -y git ``` Clone the Plotter Hub repo ``` plotter@plotterhub:~ git clone https://github.com/Synendo/PlotterHub.git ~/PlotterHub ``` Move into the installation folder ``` plotter@plotterhub:~ cd ~/PlotterHub ``` Start the installation ``` plotter@plotterhub:~/PlotterHub $ ./install.sh ``` 2. **Open the web UI** — Browse to http://plotterhub.local, or your Pi’s hostname, from any device on your network. There is no login and no desktop app to install — it works like a network printer’s web page. 3. **Drop in an SVG and set it up** — Drag and drop your SVG, select which Inkscape layers to plot, choose a paper preset and margins, and optionally enable vpype optimization. Before plotting, Plotter Hub estimates time, drawing distance, travel distance, and pen lifts. 4. **Track and control the plot** — Follow the plot live in the web UI — the pen cursor and progress bar update as it draws — and pause, resume, or cancel from there. Once the job is submitted, your computer no longer needs to stay connected. And if your plotter has a physical pause button, you can use that too, for example to resume after a layer change. ## Companion app: Design with GD Studio Plotter Hub gets your art onto paper. GD Studio is where you create it — Synendo's macOS app for generative pen-plotter art. Choose from 50 patterns across 8 families, shape them with live controls, and layer in text and imported SVG. Every design is built from continuous strokes, so the canvas shows exactly what the pen will draw. Best of all, GD Studio sends your work straight to Plotter Hub over your network — no exporting, no files to move. [Explore GD Studio](https://www.synendo.com/gdstudio/) ## Plotter Hub FAQ **Does my computer need to stay connected while plotting?** No. Once the SVG is submitted, the Raspberry Pi handles the plot locally. **Does it work with my plotter?** Plotter Hub is built for AxiDraw-class pen plotters: machines that can be controlled through the AxiDraw Python API or a compatible AxiDraw-style command workflow. Examples include: - AxiDraw plotters — for example, the AxiDraw V3/A4, V3/A3, SE/A4, or MiniKit. - AxiDraw-compatible iDraw plotters — for example, the iDraw H SE A3. - NextDraw-class plotters — for example, the NextDraw 8511 or 1117, where supported through the compatible NextDraw/AxiDraw-style workflow. - Custom EBB-based XY plotters — for advanced users, if the machine is configured to behave like an AxiDraw-class plotter. If your plotter supports the AxiDraw Python API or a compatible AxiDraw-style command workflow, it should work with Plotter Hub. **Do I need Inkscape, and what SVGs work?** Any plottable SVG works — line and stroke artwork that a pen plotter can physically draw. Inkscape isn't required either; it only matters for layer separation: if your file has Inkscape layers, Plotter Hub detects them so you can choose which ones to plot and pause between them for pen changes. Without layers, it simply plots the whole drawing. **Can I change pens between layers?** Yes. Plotter Hub can pause between layers, so you can change pens and continue the plot. **Can I pause a plot physically?** Yes, on supported plotters. The physical pause button can pause and resume a plot, and continue to the next layer during a pen-change pause. **Can I use it from another computer?** Yes. Any device on the same local network can open the Plotter Hub web interface and submit SVGs. **Does Plotter Hub have a login?** No. Plotter Hub is designed for a trusted local network, like a network printer’s web page. Do not expose it directly to the internet. For remote access, use a VPN such as Tailscale or WireGuard. **How do I update Plotter Hub?** When a newer version is published, a banner offers a one-click update right in the web UI — Plotter Hub pulls the latest version, reruns the installer, and comes back online on its own. You can also update over SSH with a git pull and rerunning ./install.sh. Updates are blocked while a plot is running, and your settings, job queue, and uploads are always kept. **Does a plot survive a reboot or restart?** Yes. Plotter Hub runs as a service and starts again on boot, and the job queue is saved to disk — so a paused plot is restored as a resumable job after a restart. Stopping the service mid-plot also raises the pen first. **Is there an API?** Yes. Plotter Hub includes an HTTP API for companion apps and scripts, secured with an auto-generated API key. See the [API documentation](https://github.com/Synendo/PlotterHub/blob/main/API.md) for the endpoint reference. **Is it free?** Yes. Plotter Hub is free and open source (MIT License).