Height Map Displacement Shader (mental ray)

The Height Map Displacement shader displaces the geometry of surfaces, and is specifically intended for use with height maps generated by normal maps; see Creating and Using Normal Bump Maps.

Material Editor > mental ray Connection rollout > For the Displacement component, turn off the lock button. > Click the button for the Displacement component. > Material/Map Browser > Maps > mental ray > Height Map Displacement
Material Editor > mental ray material > Click the button for the Displacement component. > Material/Map Browser > Maps > mental ray > Height Map Displacement

Note: mental ray shaders appear in the Browser only if the active renderer supports them.

Attention: When applying a material containing this map to an object, the mental ray Displacement

Smoothing option must be off. If such materials are applied to all objects in the scene, you can turn off Smoothing globally. Otherwise, turn off smoothing for each object whose material uses a height map via the Object Properties

mental ray panel (turn off Use Global Settings and then turn off Smoothing).

Tip: Avoid the temptation to apply MeshSmooth to a model when creating a height map for it. This changes the shape of the model so the height values will not be correct. The low-res model must have exactly the same shape when the map is created and when it is used for displacement. Also, MeshSmooth does not use the same algorithm as the mental ray displacement smoothing, so using both forms of smoothing won't work perfectly. The best results are obtained by not smoothing the low-res model when the map is created and also not using mental ray smoothing.

Also, avoid using a paint program to modify the height map. The values in the height map depend on the shape of both the low-res and high-res models, and it's easy to damage the mathematical accuracy. If you paint any changes onto the map, you must be careful to preserve the faceted look, and avoid the temptation to blur away the facets.

You might try painting in Additive and Subtractive mode to add or subtract to the displacement, because Normal mode will set a fixed displacement, making it difficult for an artist to control the result.

Interface

Height Map Displacement (3dsmax) Parameters rollout

Be sure to enter the same values for Minimum and Maximum Height as the equivalents on the Projection Options dialog, as specified below.

Minimum Height: The “Min Height” value specified on the Render to Texture: Projection Options dialog when creating the height map. Default=-10.0.
Maximum Height: The “Max Height” value specified on the Render to Texture: Projection Options dialog when creating the height map. Default=10.0.
Height Map: The height map itself (usually a bitmap).