Surface Performance
With the settings in the Surface Performance dialog it is possible to improve performance for surfaces. Read the instructions below carefully before changing any settings. Press the Restore Defaults button to return to default settings.
The most effective setting is the Quality Distance setting!
Max Camera Distance
The surface is invisible if the camera is this distance or more from the lower left corner of the surface.
Quality Style
Determines how the surface closer than Quality Distance is rendered. Full Geometry (default value) means that the surface is rendered with full geometry, and no LOD (level of detail) of any kind, while Tessellated means the surface will be tessellated once, with the best output for the LOD Precision , and the result of that tessellation will be reused in further frames without any adaptive tessellation.
Max LOD Triangles
Maximum number of LOD triangles. Triangles closer than Quality Distance do not count toward this limit.
LOD Precision
Precision of LOD surface beyond Quality Distance . The lower the value, the higher the precision and triangle count. Large values will result in a coarse surface. The surface closer than Quality Distance ignore this setting.
Occlusion Frame Skip
Numbers of frames to skip for a surface sub area when occlusion testing found it invisible. Occlusion testing can help reduce CPU requirements when tiles are occluded, either by the surface itself (triangles behind a mountain or a cliff) or by geometry that was rendered before the surface (large buildings). If there is little occlusion in your scene (such as in top down or high-altitude view), turning occlusion on may have a slightly negative effect on frame rate. It works by turning off rendering of triangles for the specified number of frames if it has been found invisible, after Frame Skip number of frames have been skipped, it will be rendered again, and a new occlusion testing made. This makes occlusion-testing a frame-to-frame coherency optimization, and as such, shouldn't be used for static rendering (ie. leave value to its default of zero). This optimization requires the hardware to support GL_NV_occlusion_query.
Occlusion Tessellate
Determines if and how occlusion testing affects tessellation. Turning off tessellation of tiles determined invisible can improve performance, however, it may result in glitches since the tessellation of an invisible triangles can have a slight effect on the tessellation of its adjacent tiles (by forcing higher resolution at the border for instance). This negative effect can be lessened by increasing the Quality Distance , so that glitches will appear farther away (this will mean increasing your triangle count though, so you'll trade CPU power)