Hello, I am working on a project to create a 3D graph of some image data. Basically it is a heightmap. The input data contains intensity (height), and from its position in the buffer I can calculate an X and Z coordinate. The data is at least 256 x 256, and can go up to 1024 x 1024.
My question is : what is the best way to render this? I'd like to be able to render new data on the fly, so a display list is out. I think an octree might work, but there would be alot of overhead if the input data changes and I have to recreate the octree.
Currently I am rendering this with triangle strips in a vertex array (see below), and getting a measly 5FPS with a 512 x 512 dataset (although I am not doing any frustum culling or anything like that). I'd also like to be able to run this on as many cards as possible.
Here's the code I am using to create the array of triangle strips:
for(int iZIndex = 0; iZIndex < (m_iHeight - 1); iZIndex++)
{
if(bSwitch)
{
for(int iXIndex = (m_iWidth - 1); iXIndex >= 0; iXIndex--)
{
SetVertexColor(m_fArray[iXIndex][iZIndex + 1], iCount);
m_pVertices[iCount].x = iXIndex;
m_pVertices[iCount].y = m_fArray[iXIndex][iZIndex + 1];
m_pVertices[iCount].z = iZIndex + 1;
iCount++;
SetVertexColor(m_fArray[iXIndex][iZIndex], iCount);
m_pVertices[iCount].x = iXIndex;
m_pVertices[iCount].y = m_fArray[iXIndex][iZIndex];
m_pVertices[iCount].z = iZIndex;
iCount++;
}
}
else
{
for(int iXIndex = 0; iXIndex < (m_iWidth - 1); iXIndex++)
{
SetVertexColor(m_fArray[iXIndex][iZIndex], iCount);
m_pVertices[iCount].x = iXIndex;
m_pVertices[iCount].y = m_fArray[iXIndex][iZIndex];
m_pVertices[iCount].z = iZIndex;
iCount++;
SetVertexColor(m_fArray[iXIndex][iZIndex + 1], iCount);
m_pVertices[iCount].x = iXIndex;
m_pVertices[iCount].y = m_fArray[iXIndex][iZIndex + 1];
m_pVertices[iCount].z = iZIndex + 1;
iCount++;
}
}
bSwitch = !bSwitch;
}
Then I set up the vertex arrays :
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_COLOR_ARRAY);
glVertexPointer(3, GL_FLOAT, sizeof(CVector3), &(m_pVertices->x));
glColorPointer(3, GL_FLOAT, sizeof(CVector3), &(m_pVertices->R));
And finally I render:
glBegin(GL_TRIANGLE_STRIP);
for(int i = 0; i < m_iTotalPoints; i++)
{
glArrayElement(i);
}
glEnd();
Any help or ideas would be greatly appreciated! Thanks.
[Edited by - tritone on August 4, 2004 12:42:38 PM]
