Applying Geometry Shaders

Geometry shaders are applied to geometry shader objects, which are special objects that have a GeoShader property.

Geometry shader object (A) and its GeoShader property (B).

Applying a geometry shader is a two-step process:

Get a geometry shader primitive.
Add geometry shaders to the GeoShader property and modify its parameters as needed.

Getting Geometry Shader Objects

A geometry shader object is a placeholder in your scene for the geometry that will be created by your shader in mental ray.

Choose Get Primitive Geometry Shader Primitive from any toolbar. The GeoShader property editor opens.

You can add geometry shaders as described in the next section.

By itself, the geometry shader object does not create any geometry. You must apply a geometry shader that does create the geometry for rendering.

Select the geometry shader object and press 7 to open the render tree.
From the preset manager, drag a geometry shader into the render tree and connect it to the GeoShader's Geometry Shader input.