Setting Tessellation Parameters - Lumberyard User Guide

Setting Tessellation Parameters

Open 3D Engine (O3DE), the successor to Lumberyard, is now available in Developer Preview. Download O3DE or visit the AWS Game Tech blog to learn more.

To apply tessellation to an object and set parameter values, complete this procedure.

To apply tessellation to an object

  1. In Material Editor, click Tools, Material Editor.

  2. In the left tree, click to select the desired asset.

  3. In the right pane, under Shader Generation Params, select either Phong tessellation or PN triangles tessellation.

  4. Under Shader Params, adjust the values of the following parameters.

Tessellation Parameters
Parameter Description
Tessellation face cull Specifies the extent to which vertices are culled. Because tessellation uses its own face culling, it takes the original (non-tessellated) triangle and checks if it's facing the camera; if not it discards it.

This can also be used for 2-sided sorting of polygons. In this case, the 2 Sided check box must also be selected under Advanced in the Material Editor.

An issue may arise when there is displacement that is visible from the camera. For example, a bump on a cube that is rotating is still visible for a while, even though the cube face is no longer facing the camera.

Setting this parameter to 0 means no face culling at all, while setting it to 1 will cull anything not facing the camera.

Tessellation factor Specifies the density of the mesh triangles
Tessellation factor max Used for objects that are at a fixed distance or range from the camera to get rid of geometry “popping” artifacts. This is useful for cutscenes.
Tessellation factor min Setting this value to 1 means that it will be always tessellated at level 1, even if the object is far away from camera.