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Surface Shading

The Surface object shader is more simple than the volumetric, as it can only have one color, although it can have many properties. The shader does not explicitly load the data, as the data interaction is all done through the threshold in the Geometry options.

surface shader overview

Color LUT

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The color lookup table works similar to the volume color LUT. However, the surface can only display one value, so the Fac value defines where along the lookup table the color is drawn from.

For a regular color picker you can leave the Fac at 1 and click the rightmost handle. The other way would be to replace this box with a color box (Add > Input > RGB)

Mesh shading

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The Principled BSDF node is a combined node that combines features to create different material properties. The Blender manual gives a complete manual to its features.

By default this has two inputs set differently from Blender default, the Base Color and Emission Color/Strength. These colors are set to link to the Color LUT.

The Emission Strength is set to 0 or 0.5 depending on whether this was loaded with emission on or emission off. This is done for consistency, and that dark scenes have masks and surfaces as clearly visible as data, without setting up lighting.

Emission can 'flatten' objects

The feeling of depth in 3D rendering is often due to the interaction of objects with light. When things are emitting light themselves, they can often look flat. For more feeling of depth, it might be better to load with emission off, and set up some form of lighting.

Slice cube

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The Slice Cube section allows slicing of the surface. This has an Object pointer to a cube in the scene (by default the loaded slice cube).

The object bounding box gets fed into the slicer, which hides all regions outside the bounding box.

How this works

The slicing node uses the remapped positions from the Texture Coordinate node, compares them to the cube bounds, and removes everything outside that cube space. This makes the surface behave consistently with the volume slicer while still staying a regular mesh shader.