Color Combine

Combines four separate input textures into the red, green, blue, and alpha channels of a single output.

Category: Color Menu path: Color > Color Combine

Ports

Port	Type	Direction	Description
r_in	imageRgba16f	input	Red channel source (luminance is extracted)
g_in	imageRgba16f	input	Green channel source (luminance is extracted)
b_in	imageRgba16f	input	Blue channel source (luminance is extracted)
a_in	imageRgba16f	input	Alpha channel source (luminance is extracted)
out	imageRgba16f	output	Combined RGBA result

Parameters

This node has no parameters.

How It Works

Each input texture's luminance (Rec. 709) is extracted and placed into its corresponding output channel. Disconnected R/G/B inputs default to transparent (0). A disconnected alpha input defaults to opaque white (1). The output is premultiplied.

This is the inverse operation of Color Split. Together they allow you to process individual channels independently and recombine them.

Usage Examples

Basic: Recombine split channels

1. Use a Color Split node to separate an image into R, G, B, A
2. Process each channel individually (e.g. blur only the red channel)
3. Feed all four processed channels back into a Color Combine node

Creative: Channel swap

1. Split an image with Color Split
2. Connect the R output to Color Combine's b_in and B output to r_in
3. The resulting image has swapped red and blue channels

Advanced: Build RGBA from separate sources

1. Use different Noise generators for R, G, and B channels
2. Use a Gradient for the alpha channel
3. Color Combine merges them into a single textured image with shaped transparency

Tips

• Each input extracts luminance, not a specific channel -- feed in grayscale images for predictable results
• Disconnected R/G/B inputs produce black (0) in that channel; disconnected A produces opaque (1)
• This node has no single in port, so it acts as a terminal merge in the node graph (not a passthrough)

Related Nodes

• Color Split -- the inverse operation: splits one image into per-channel outputs
• Merge -- layer compositing (different from channel combination)
• Mix -- blend two images with a mask