ComfyUI-AlvatarUtils

Custom nodes for ComfyUI focused on 3D asset production pipelines: background removal, image preparation, 4x upscaling, GLB mesh loading with PBR texture extraction, Blender-based AO baking and texture rebaking, and workflow utilities.

Nodes

Image (Alvatar/Image)

Background Removal

High-quality background removal using RMBG-2.0 (BiRefNet) or BEN2. Returns a foreground image and alpha mask.

Input	Type	Default	Description
image	IMAGE	—	Input image(s), supports batch
model	choice	RMBG-2.0	RMBG-2.0 (best quality) or BEN2 (good edges)
sensitivity	FLOAT	1.0	Mask detection sensitivity (0.0–1.0)
process_res	INT	1024	Internal processing resolution (256–2048)
mask_blur	INT	0	Gaussian blur on mask edges (0–64)
mask_offset	INT	0	Expand/shrink mask boundary (-64 to 64)
refine_foreground	BOOL	False	Apply Fast Foreground Color Estimation
background_color	choice	none	none / white / black

Outputs: image (IMAGE), mask (MASK)

Prepare Image for 3D

Detects the foreground object, centers it, and produces a square crop ready for 3D generation (Trellis2, Hunyuan3D, UltraShape, etc.).

Input	Type	Default	Description
image	IMAGE	—	Input image(s)
detection_method	choice	auto	auto, alpha, uniform_background, threshold, edge, grabcut
margin	FLOAT	0.1	Padding around detected object (0.0–0.5)
output_size	INT	0	Final square size in px (0 = keep natural)

Outputs: image (IMAGE)

Detection methods: alpha (use existing transparency), uniform_background (solid-color backgrounds), threshold (Otsu), edge (Canny), grabcut (complex scenes, slowest), auto (tries alpha → uniform → grabcut).

Upscale 4x

4x super-resolution using SOTA models via Spandrel. Tile-based processing for VRAM efficiency.

Input	Type	Default	Description
image	IMAGE	—	Input image(s)
model	choice	DRCT-L	DRCT-L (best reconstruction), HAT-GAN Sharp (sharpest), UltraSharp (best for JPEG)
downsize	INT	0	Downsize after 4x for supersampling (0 = no downsize)
tile_size	INT	256	Processing tile size (128–1024)
tile_overlap	INT	32	Overlap between tiles (8–128)

Outputs: image (IMAGE)

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3D Mesh (Alvatar/3D)

Load GLB to Trimesh

Loads a mesh file from ComfyUI's input directory and extracts all embedded PBR textures in glTF format.

Input	Type	Description
mesh_file	file dropdown	GLB, GLTF, OBJ, PLY, STL

Outputs: trimesh (TRIMESH), file_path (STRING), albedo (IMAGE), normal (IMAGE), metallic_roughness (IMAGE), occlusion (IMAGE)

Texture channels follow glTF convention: metallic_roughness has G=Roughness, B=Metallic; occlusion has R=AO.

Load GLB from Path

Same as above but takes a path string instead of a file dropdown. Useful for chaining with nodes that output file paths.

Input	Type	Description
file_path	STRING	Absolute or relative path to mesh file

Outputs: trimesh (TRIMESH), albedo (IMAGE), normal (IMAGE), metallic_roughness (IMAGE), occlusion (IMAGE)

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Texture (Alvatar/Texture)

Blender AO Baker (Path)

Bakes ambient occlusion from a mesh file using Blender Cycles (headless).

Input	Type	Default	Description
mesh_path	STRING	—	Path to mesh file
resolution	INT	2048	AO texture resolution (256–8192)
samples	INT	64	Cycles render samples (1–512)
ao_distance	FLOAT	1.0	Max occlusion ray distance (0.01–100)
use_gpu	BOOL	True	Use CUDA for rendering
margin	INT	16	UV island margin in pixels (0–64)

Outputs: ao_image (IMAGE), ao_path (STRING)

Blender AO Baker (Trimesh)

Same baking as above but accepts a TRIMESH input and passes it through for chaining.

Outputs: ao_image (IMAGE), ao_path (STRING), trimesh (TRIMESH)

Blender Rebake Textures

Transfers PBR textures (albedo, normal, roughness, metallic) from a source mesh onto a target mesh with different topology. Uses Blender Cycles ray-casting. Does not transfer AO — bake that separately with BlenderAOBaker.

Input	Type	Default	Description
source_trimesh	TRIMESH	—	Source mesh (has the textures)
target_trimesh	TRIMESH	—	Target mesh (receives the textures)
albedo	IMAGE	—	Albedo / base color texture
normal	IMAGE	(optional)	Normal map
metallic_roughness	IMAGE	(optional)	glTF format (G=Roughness, B=Metallic)
resolution	INT	2048	Output texture resolution (256–8192)
samples	INT	64	Cycles samples (1–256)
uv_method	choice	angle_based	angle_based, smart_project, lightmap
seam_angle	FLOAT	66.0	Seam angle threshold (10–89)
cage_extrusion	FLOAT	0.05	Cage inflation for baking (0.001–1.0)
max_ray_distance	FLOAT	0.1	Max ray travel distance (0.01–2.0)
margin	INT	16	Texture bleed margin (0–64)
use_gpu	BOOL	True	Use CUDA for rendering
debug_mode	BOOL	False	Save .blend file for inspection

Outputs: baked_albedo (IMAGE), baked_normal (IMAGE), baked_roughness (IMAGE), baked_metallic (IMAGE), glb_path (STRING), trimesh (TRIMESH)

Make ORM

Packs three grayscale textures into a single ORM texture (R=AO, G=Roughness, B=Metallic). Standard PBR channel packing.

Input	Type	Description
ao	IMAGE	Ambient Occlusion → Red channel
roughness	IMAGE	Roughness → Green channel
metalness	IMAGE	Metalness → Blue channel

Outputs: orm (IMAGE)

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Utilities (Alvatar/Utils)

Resolve Path

Resolves a relative path to absolute by searching output/, input/, and temp/ directories. Useful for connecting nodes that save files with nodes that load by path.

Outputs: absolute_path (STRING)

Debug Any

Accepts any input type, displays type info (shape, dtype, device, value preview) in the node UI, and passes the value through unchanged.

Outputs: output (*), debug_text (STRING)

Continue 3

Synchronization barrier with 3 passthrough channels (all optional). Forces all connected inputs to complete before any output is available. Useful for VRAM management and parallel branch synchronization.

Outputs: output1 (), output2 (), output3 (*)

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Requirements

Python packages (beyond what ComfyUI provides):

trimesh
Pillow
opencv-python-headless
spandrel
safetensors
transformers

System dependencies:

• Blender 3.0+ (for AO baking and texture rebaking nodes)
• CUDA-capable GPU (optional, for GPU-accelerated baking and upscaling)

Installation

Clone into ComfyUI's custom_nodes directory:

cd ComfyUI/custom_nodes
git clone https://github.com/alvatar/ComfyUI-AlvatarUtils.git
pip install -r ComfyUI-AlvatarUtils/requirements.txt

Restart ComfyUI. All nodes appear under the Alvatar/ category.

License

MIT