2 replies to this topic

[PhillipHamlyn]

Hi,

 

Does anyone have a general rule for the number of triangles they'd budget on for a terrain, after frustum culling has taken place ? I've got a tiled LOD system, and before I start optimising I'd like a steer on what people tend to aim at. My optimisation steps will be based on measurement-change-remeasure, but I dont want to strive for a high level of geometry if most people aim for (for instance) 50k triangles, and dont see a need to optimise beyond that to achieve a higher triangle count.

 

Thanks

 

Phillip

[swiftcoder]

Effective texture resolution is often just as important as geometry detail (especially when using normal mapping). I generally try to aim for ~2 texels per pixel (or more, if multisampling is enabled).

 

As for geometry, the primary goal is to provide smooth silhouettes (since normal mapping doesn't help there). Ideally, you want ~1 vertex per pixel near silhouette edges, and can get away with drastically less everywhere else.

 

If you are using tessellation + displacement mapping this can be very simple/fast - you keep a fairly low-resolution control grid around, and use that to dynamically increase tessellation for just the silhouette.

[PhillipHamlyn]

Effective texture resolution is often just as important as geometry detail (especially when using normal mapping). I generally try to aim for ~2 texels per pixel (or more, if multisampling is enabled).

 

As for geometry, the primary goal is to provide smooth silhouettes (since normal mapping doesn't help there). Ideally, you want ~1 vertex per pixel near silhouette edges, and can get away with drastically less everywhere else.

 

If you are using tessellation + displacement mapping this can be very simple/fast - you keep a fairly low-resolution control grid around, and use that to dynamically increase tessellation for just the silhouette.

Thanks swiftcoder. I'll try increasing my texture realism and already use bump mapping so I might get  a suprisingly good result from the approach you advise.