Houdini 20.5 Nodes Copernicus nodes

Height to Ambient Occlusion Copernicus node

Imagines a sphere for each pixel and determines how occluded that sphere is based on its surroundings.

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For each pixel, this node imagines a sphere and then determines how occluded that sphere is based on the height values of its neighboring pixels. For example, if you're standing on pixel (450, 450) and that pixel’s in a valley with mountains around it, the sphere is occluded because the mountains block the sun’s rays.

Before and after using the Height to Ambient Occlusion node.

The Height to Ambient Occlusion node is useful for shading and texture synthesis. You can use this node to create an ambient occlusion map for a material or as a mask to perform other operations. For example, use this node to add dirt to your material and use the ambient occlusion map to determine where the dirt lies.

Note

This node is based on the HeightField Mask by Occlusion geometry node.

Parameters

Height

Height Scale

The amount (in image space) to scale the height values of the input layer’s pixels, which controls the length of the shadows. Higher values increase the height of the pixels and darken their grayscale. Lower values decrease the height of the pixels and lighten their grayscale.

The default value is 0.01. You should set this parameter to lower values since Copernicus uses image space.

Note

Though lower values can make the pixel appear flat (all similar shades of white), the pixel may be elevated. Use the pixel inspector to confirm whether the pixel is flat.

For example, if you set Height Scale to 1 and your input’s width is a value of 2, the result is that black to white is an increase in elevation to the same height value as half of the image’s width (1). To preview the Height Scale, you can wire your output into the Preview Material COP’s height input (see the following example image).

Quality

View Radius

The distance (in image space) to send rays to determine if a pixel’s occluded. Higher values increase the distance you send the rays and provide more accurate measurements, but may slow cooking. Lower values decrease the distance you send the rays.

The default value is 0.2.

Step Scale

How many steps (in buffer space) to take along the rays to determine if a pixel’s occluded. Higher values create less steps and therefore cook faster, but may miss thin features since the steps are more spread out. Lower values create more steps, which are closer together.

The default value is 0.5.

Sample Count

The amount of rays to send to determine if a pixel’s occluded. Higher values increase the amount of rays sent and provide more accurate measurements, but may slow cooking. Lower values decrease the amount of rays sent.

The default value is 20.

Sample from Hemisphere

Divides the point’s calculated angle by 90 degrees instead of 180 degrees.

Remap Ramp

Remaps the output ambient occlusion values.

For more information about using ramps, see Ramp parameters.

Inputs

layer

The original height layer from which to calculate the ambient occlusion.

Outputs

occlusion

The ambient occlusion layer.

Copernicus nodes