Creating heightmap of an existing terrain-mesh?
Posted: Tue May 23, 2006 8:01 am
Hi all,
I don't know if this is the right topic for the advanced forum. I have an existing terrain-mesh modeled in max and exported to a directx-file. I want to use the cool grass node system presented by bitplane and tried to create a heightmap from my terrain.
So far i have written the height of all vertices to an image, translating it to greyscale values. but I don't know how to interpolate the greyscale values between the vertices positions. Is there any other plan how to sample the height of a mesh? I mean, not sampling the vertex positions, but the triangles heights at the sampling point. Can this be done with the triangleselector? Didn't find any function for that.
Thanks
Robert
This is my code so far:
I don't know if this is the right topic for the advanced forum. I have an existing terrain-mesh modeled in max and exported to a directx-file. I want to use the cool grass node system presented by bitplane and tried to create a heightmap from my terrain.
So far i have written the height of all vertices to an image, translating it to greyscale values. but I don't know how to interpolate the greyscale values between the vertices positions. Is there any other plan how to sample the height of a mesh? I mean, not sampling the vertex positions, but the triangles heights at the sampling point. Can this be done with the triangleselector? Didn't find any function for that.
Thanks
Robert
This is my code so far:
Code: Select all
aabbox3d<float> myBB = pTrackMesh->getBoundingBox();
const u16 WIDTH = 512;
const u16 HEIGHT = 512;
float minEdgeX_terrain = myBB.MinEdge.X;
float minEdgeZ_terrain = myBB.MinEdge.Z;
float minEdgeY_terrain = myBB.MinEdge.Y;
float maxEdgeX_terrain = myBB.MaxEdge.X;
float maxEdgeZ_terrain = myBB.MaxEdge.Z;
float maxEdgeY_terrain = myBB.MaxEdge.Y;
float dimX_terrain = maxEdgeX_terrain - minEdgeX_terrain;
float dimY_terrain = maxEdgeY_terrain - minEdgeY_terrain;
float dimZ_terrain = maxEdgeZ_terrain - minEdgeZ_terrain;
float indexX_map, indexZ_map;
vector3df vertexPos;
float greyValue;
int index;
dimension2d<s32> size;
size = dimension2d<s32>(WIDTH, HEIGHT);
RGB_PIXEL pixels[WIDTH*HEIGHT];
for (int b = 0; b < pTrackMesh->getMeshBufferCount(); b++)
{
IMeshBuffer* pMeshBuffer = pTrackMesh->getMeshBuffer(b);
void* vertices = pMeshBuffer->getVertices();
for(int a = 0; a < pMeshBuffer->getVertexCount(); a++)
{
//get Pos of a single vertex
vertexPos = ((S3DVertex*)vertices)[a].Pos;
//get Pos on height map
indexX_map = u16((vertexPos.X - minEdgeX_terrain) * WIDTH / dimX_terrain);
indexZ_map = u16((vertexPos.Z - minEdgeZ_terrain) * HEIGHT / dimZ_terrain);
greyValue = (vertexPos.Y - minEdgeY_terrain) * 256 / dimY_terrain;
index = int(indexZ_map * WIDTH + indexX_map);
pixels[index].r = u8(greyValue);
pixels[index].g = u8(greyValue);
pixels[index].b = u8(greyValue);
}
}
IImage* myImage = pDriver->createImageFromData(ECF_R8G8B8, size, pixels, true);
pGuienv->addImage(pDriver->addTexture("TEST", myImage), position2d<s32>(50, 50));