The node calculates measures occlusion as "how much of a sphere centered on the point is visible from the given point." It sends rays from each point in different directions and measures how many hit terrain before reaching their maximum distance.
Combine with Existing
How to combine this mask with any existing mask in the input.
Clear the existing mask and replace it with the new mask.
Add the values in this mask to any existing mask.
Subtract the values in this mask from any existing mask.
Set the mask values to the difference between the old mask and this mask.
Multiply the values of the old mask by the values in this mask. This might be useful to "scale" existing values while leaving empty areas alone.
Set the mask values to the maximum of the old mask and this mask.
Set the mask values to the minimum of the old mask and this mask.
Blend the old mask and this mask by a certain amount.
The amount to blend the old mask with what you draw, when Combine with existing is "blend". A value of
0 leaves the existing mask, a value of
1 replaces with the new mask, a value of
0.5 blends equally between the old and new mask.
Minimum Occlusion: Minimum occlusion to mask.
Maximum Occlusion: Maximum occlusion to mask.
A ramp mapping the sunlight exposure at a given point (ranging from 0 to 1, with higher values being more exposed) to the mask value at that point.
Sample from Hemisphere: Sample from Hemisphere.
How far to send rays to determine if a point can see the sky. Longer distances give more accurate measurements, but can be slower. A value of 0 corresponds to a view distance of infinity.
How finely to step along the rays to determine if a point can see the sky. Larger values are faster but might miss thin features.
Number of Searches
How many rays to send to determine if a point can see the sky. Larger numbers give more accurate measurements, but can be slower.
If a mask volume is wired into this node’s second input, this specifies which volume in the second input to use to mask this node’s effect, usually
mask. Click the "Add mask paint" button to paint the mask directly in the viewport (this automatically adds a paint node to the second input).
The name of the height volume to operate on, usually