SVG Rasterizer

<p align="center"> <img src="assets/banner.png" alt="ComfyUI SVG Rasterizer — vector artwork converted to raster image and alpha mask" width="100%"> </p>

ComfyUI SVG Rasterizer

A small ComfyUI custom node that renders native SVG values directly to a user-selected resolution. It is intended for clean, high-resolution silhouette and line-art exports, including 6144 x 6144 PNG output.

The node produces:

• IMAGE: RGB float32 tensor in the 0-1 range, shaped [B, H, W, 3].
• MASK: original SVG alpha coverage as a float32 tensor in the 0-1 range, shaped [B, H, W]. 0 is transparent and 1 is fully covered.

Native SVG support

The input socket is SVG, not STRING. Current ComfyUI represents this type as an SVG wrapper with a .data list containing one BytesIO stream per batch item. This node reads that representation directly and also accepts byte, text, file-like, and simple structured payloads for compatibility. It does not depend on Potracer's deprecated svg_string output.

References used for the implementation:

• ComfyUI native SVG class
• ComfyUI Save SVG node

Installation

Copy this directory to:

ComfyUI/custom_nodes/ComfyUI-SVG-Rasterizer/

Restart ComfyUI. On the first restart, the package checks for resvg_py, Pillow, and NumPy. If any are missing, it installs requirements.txt using the exact Python executable running ComfyUI. This works with the embedded Python in ComfyUI Portable and with the active environment in ComfyUI Easy Install.

The automatic check does not run pip again after all dependencies are present. The first installation requires internet access. Installation progress or any failure is printed in the ComfyUI server console.

Manual fallback

Install the dependencies into the same Python environment that runs ComfyUI, then restart ComfyUI. resvg_py provides prebuilt Windows wheels and does not require GTK, Cairo, Rust, a compiler, or manual DLL configuration:

python -m pip install -r ComfyUI/custom_nodes/ComfyUI-SVG-Rasterizer/requirements.txt

For the standard Windows portable build, run this from the portable root:

python_embeded\python.exe -m pip install -r ComfyUI\custom_nodes\ComfyUI-SVG-Rasterizer\requirements.txt

For ComfyUI Easy Install, open its terminal/environment and run the first command with that environment's python executable.

Workflow

Potracer to SVG
      | SVG
      v
SVG Rasterizer
  width      = 6144
  height     = 6144
  background = white
      | IMAGE
      v
Save Image

Connect the Potracer node's native SVG output directly to this node's svg input. No text conversion node is needed.

Settings

• width / height: output canvas dimensions from 64 to 16384 pixels. The default is 6144 x 6144.
• background = white: recommended for typical black silhouettes.
• background = black: composites the SVG over solid black.
• background = transparent: leaves RGB uncomposited and carries the original transparency in the separate MASK output. Standard ComfyUI IMAGE output is RGB, so use the mask when saving or compositing transparency.

resvg renders the vector geometry directly at the requested dimensions; there is no low-resolution intermediate, Pillow resize, or AI upscaling step. SVG viewBox and preserveAspectRatio behavior are honored by resvg, so non-square artwork is fitted according to its SVG geometry rather than being post-resized as a bitmap. When the SVG and requested canvas have different aspect ratios, the directly rendered result is centered on a transparent canvas before background compositing; it is never bitmap-resized.

For crisp silhouette results, keep the Potracer source clean, use the final export dimensions here, choose white for black-on-white artwork, and connect the resulting IMAGE directly to ComfyUI's Save Image node.

Errors

The node reports clear errors for missing or unsupported SVG payloads, malformed SVG documents, dimensions outside the supported range, and resvg rendering failures.