Efficient Landscape Mesh Optimization

Question

I need to render an expansive landscape on a render target which lacks the ability to do heightmap-based displacement or mesh subdivision operations in hardware. Thus my only option is to bake the mesh and split it into separate static models to be loaded and unloaded when needed.

As for the landscape mesh itself, being a displaced subdivided plane, there are many relatively flatter/less dense in detail areas in the mesh that don't need nearly as many quads to be represented, but other than going through the entire mesh by hand I don't know how I can efficiently optimize the landscape.

Is there a script/workflow/outside program that can take a mesh of quads and convert it into a mesh of more efficiently-placed triangles/quads based on the shape topology? I don't know if this is the best way to word it so if more explanation is needed please ask.

Answer 1

A landscape mesh can be simplified, while retaining most of the shape, using a combination of tools.

• The decimate modifier using the planar option
• Triangulating the mesh in the edit mode

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Example:

This is a mesh for a portion of Bryce Canyon formed from a quad mesh. It has about 21,000 vertices.

Applying the decimate modifier with the planar option selected and 3degrees, then applying removes about 1/2 of the vertices, leaving about 13,000 vertices.

After applying the modifier and entering edit mode, the resulting mesh has the flat regions automatically merged. A final step is to triangulate the mesh in edit mode.

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Note, there are other tools in edit mode that can help simplify the mesh:

• Select > Sharp Edges to select edges with high angles
• Mesh > Clean Up > Limited Dissolve to eliminate edges with low angles
• Mesh > Clean Up > Degenerate Dissolve to eliminate long skinny facets