mia_roundcorners
 
 
 

Category: mental ray > Texture

Shader Family: Texture

Output: Vector

Related Softimage shader: Round Corners (mia)

This shader creates the illusion of rounded edges at render time. It is primarily intended to prevent the unnecessary modelling of details; for example, if you use this shader, you don't need to create a table top with actual filleted or chamfered edges.

Because the edges of computer-generated object often look too sharp, this shader is useful for making edges look more realistic (rounded, chamfered, worn, or filleted in some way). Rounded edges tend to catch the light and create highlights that make edges more visually appealing.

The shader doesn't displace geometry: it is merely a shading effect (like bump mapping) and is best suited for straight edges and simple geometry, not advanced highly curved geometry.

Name

The name of the shader node displayed in the render tree. Enter any name you like, or leave the default.

radius

Defines the radius of the rounding effect in global space units.

allow_different_materials

Allows rounding to happen on any face of any material. When this parameter is off, rounding happens only on faces with the same material.

bump

The bump input accepts a shader that perturbs the normal for bump mapping. This port is only used if bump_mode is set to 0 (zero).

bump_mode

The bump modes allow you to define the coordinate-space of the bump_vector, as well as that of the return value of the shader itself (which is also a vector), and whether or not it is interpreted as a "normal vector perturbation" or a whole new "normal vector".

The modes are as follows:

  • 0: compatible mode. The old bump parameter is used in place of bump_vector. The return value is 0,0,0, and the shader actually perturbs the normal vector itself.

  • 1: "add" mode in "internal" space

  • 2: "add" mode in world space

  • 3: "add" mode in object space

  • 4: "add" mode in camera space

  • 5: "set" mode in "internal" space

  • 6: "set" mode in world space

  • 7: "set" mode in object space

  • 8: "set" mode in camera space

The add modes mean that the vector should contain a normal perturbation, that is, a modification is "added" to the current normal. Whereas, the set modes mean that the actual normal is replaced by the incoming vector, and interpreted in the world, object, or camera coordinate space.

Equally for output, an Add mode implies that the shader returns a perturbation vector intended to be added to the current normal, and Set mode implies that it returns a whole normal vector. In neither case does the shader actually modify the current normal by itself.

bump_vector

The bump_vector input accepts a shader that perturbs the normal for bump mapping. This port is used when bump_mode is not set to 0 (zero).

Render Tree Usage

This shader perturbs the normal vector, and should be applied where bump maps are normally used, such as the bump parameter on a surface shader. You can also use it in conjunction with the shader mia_material.