Hi
I have a procedurally generated tiled landscape, and want to apply 'regional' information to the tiles at runtime; so Forests, Roads - pretty much anything that could be defined as a 'region'. Up until now I've done this by creating a mesh defining the 'region' on the CPU and interrogating that mesh during the landscape tile generation; I then add regional information to the landscape tile via a series of Vertex boolean properties. For each landscape tile vertex I do a ray-mesh intersect into the 'region' mesh and get some value from that mesh.

For example my landscape vertex could be;

struct Vtx
{    
   Vector3 Position;   
   bool IsForest;   
   bool IsRoad;   
   bool IsRiver;
}

I would then have a region mesh defining a forest, another defining rivers etc. When generating my landscape veretexes I do an intersect check on the various 'region' meshes to see what kind of landscape that vertex falls within.

My ray-mesh intersect code isn't particularly fast, and there may be many 'region' meshes to interrogate, and I want to see if I can move this work onto the GPU, so that when I create a set of tile vertexes I can call a compute/other shader and pass the region mesh to it, and interrogate that mesh inside the shader. The output would be a buffer where all the landscape vertex boolean values have been filled in.

The way I see this being done is to pass in two RWStucturedBuffer to a compute shader, one containing the landscape vertexes, and the other containing some definition of the region mesh, (possibly the region might consist of two buffers containing a set of positions and indexes). The compute shader would do a ray-mesh intersect check on each landscape vertex and would set the boolean flags on a corresponding output buffer.

In theory this is a parallelisable operation (no one landscape vertex relies on another for its values) but I've not seen any examples of a ray-mesh intersect being done in a compute shader; so I'm wondering if my approach is wrong, and the reason I've not seen any examples, is because no-one does it that way. If anyone can comment on;

• Is this a really bad idea ?
• If no-one does it that way, does everyone use a Texture to define this kind of 'region' information ?
  • If so - given I've only got a small number of possible types of region, what Texture Format would be appropriate, as 32bits seems really wasteful.
• Is there a common other approach to adding information to a basic height-mapped tile system that would perform well for runtime generated tiles ?

Thanks

Phillip