Several render channels are available, useful for compositing tasks. You can enable the channels you need and choose the file format for each channel.

The output will be saved in the same directory as set in the Output options.

Available channels


Channels panel


Aside from the usual standard channels, some other may need a more detailed description: 

  • Roughness: Output an image containing the Roughness value of the materials in the scene. High Roughness materials will appear white in the image, while low Roughness materials will appear dark.
  • Fresnel: Output an image containing the Fresnel information of the surfaces. 
  • Normals: Output an image containing the Normals distribution. They can be calculated both in Word coordinates or in Camera coordinates.
  • Position: Output an image containing the X, Y, and Z position of each pixels in the image. They can be calculated both in Word coordinates or in Camera coordinates.

The following image gives you an idea of what the different channels from Maxwell look like and an example of the final image after compositing several of them together using Photoshop. Please see the page of each channel to better understand how to use the channels for compositing.

  1. The background image 
  2. The ground rendered alone 
  3. Alpha channel
  4. Objects ID channel
  5. Material ID channel
  6. Ground shadows
  7. Car shadows
  8. Roughness channel
  9. Fresnel channel
  10. Position channel (X, Y and Z) 
  11. Normals channel (World coordinates) 
  12. Normals channel (Camera coordinates) 
  13. Diffuse pass
  14. Reflections Pass
  15. Z-buffer channel
  16. The final composition

Output mode

Choose whether you want your channels to be exported as independent files (Separate), or embedded as one single file (Embedded) in the formats that allow extra buffers, such as EXR or TIF. The Alpha channel can be embedded in the TGA, PNG, TIF and EXR formats.

Displaying a channel while rendering

During the render, you can display the specific render channels that you’ve requested by hovering over the channel buttons in the render view.  



Channels icons

The icons represent:

R: Render channel
A: Alpha channel
S: Shadow channel
M: Material ID channel
O: Object ID channel
M: Motion vector channel
Z: Depth channel
R: Roughness channel
F: Fresnel channel 
N: Normals channel 
P: Position channel


If the Multilight feature is enabled, Maxwell exports all the shadow buffers corresponding to each individual light emitter separately during the same render process, as well as a shadow pass of all the shadows cast by each emitter “blended” together, giving an extraordinary control over the compositing during the post-production process.

For example you can change the brightness of an emitter using MultiLight which could then brighten up the shadow cast by another emitter. The blended shadow pass image will take these changes into account.