The Height Field Visualize node has better controls for visualizing mask layers.
Houdini supports a default visualization for height fields that shows the
height field as a 3D surface and the
mask field as a red tint on the surface.
This node simply copies a given layer into the mask layer or the height layer, to let you use the default visualization to visualize a different layer (for example, the
mesa mask layer created by Heightfield Clip).
The output of this node is the height field and mask you see in the viewport. That means it changes the
mask layer, and if you turn on Overwrite height, it zeroes the
If you are using this node to visualize a layer, you should branch it off the network and not use its output.
You could theoretically use the output of this node if you just want to copy another layer into the height field or mask, but you should probably use the appropriate dedicated node (Heightfield Copy Layer) instead to make the network more understandable.
Layer to Isolate
The name of the layer to copy into the
Replace the existing height field with the isolated layer. This
Replace the existing mask with the isolated layer.