if (FuncAsTexture)

Every programming language has an if/else, and this node is the image version: if imga ≥ a threshold, output imgb; otherwise output imgc. The display name is literally if (FuncAsTexture), in the same spirit as Unreal's material node that shares the name. It's a per-pixel conditional, which means the "decision" happens independently at every pixel - a mask-driven switch between two images.

The mechanism is a two-way blend computed with weights that are never fractional. The formula:

lessweight = np.floor(1 - imga + pfloat1)
largeweight = np.ceil(imga - pfloat1)
result = imgb * largeweight + imgc * lessweight

np.floor and np.ceil snap the weights to 0 or 1, so there's no smooth gradient at the boundary - each pixel takes fully from one image or the other. imga is the decision image (bright = take imgb, dark = take imgc), and pfloat1 is the threshold it's compared against, default 0.5. The tooltips spell it out: imgb is "Output 1, when imga ≥ pfloat1," imgc is "Output 2, when imga < pfloat1."

Where you'll use it

• Mask-driven compositing. You have a mask and two content images. Feed the mask into imga, set the threshold, and the output is whichever content the mask selects, per pixel. This is a hard-edged (mask-based) switch - the pack's Lerp would do the soft version, but this one is crisp by design.
• Thresholding anything. Take a distance map, set the threshold, and turn it into a binary region selector.
• Chained conditionals. Since the output is an image, you can feed one ifFunction's output into another's imga - building nested if/else ladders that would be a nightmare in any other UI.

Inputs and outputs

• formula - the conditional script, pre-filled and editable.
• imga - the decision image (reference for output resolution).
• imgb - chosen where imga ≥ pfloat1.
• imgc - chosen where imga < pfloat1.
• pfloat1 - the threshold, 0–1, default 0.5.

One IMAGE output.

Install

ComfyUI Manager → search "FuncAsTexture", or:

cd ComfyUI/custom_nodes
git clone https://github.com/CoiiChan/ComfyUI-FuncAsTexture-CoiiNode
# restart ComfyUI

No models, no requirements.txt. Category: FunctionAsTexture.

Gotchas

• The switch is per-pixel and hard. There's no anti-aliasing at the boundary - the transition is a one-pixel step. If you want a feathered edge, soften the decision image (or use a lerp formula instead).
• The threshold compares against imga's value at each pixel, including its color channels separately if imga is RGB. A gray decision image behaves as you expect; a colored one will make different channels switch at different times. Feed it grayscale unless you want that.
• imga defines the output resolution - make sure your two content images match it, or NumPy will complain.

It's the pack's decision node, and it's the one that makes "mask selects content" a single node instead of a graph. For anything where the output needs to be one of two things at every pixel - not a blend - this is the tool.