Orthogonal and perspective projection combination
Author
Hi!
Simple question… How to combine «together» glOrtho and gluPerspective?
The problem description is – I render voxel based landscape using glOrtho (it’s only one way), but then, I must add 3d models… As far as I understand I must use perspective projection for models…
I’m not expert in OpenGL, and I found simple solution:
void Render()
{
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
glOrtho(0, 1024, 0, 768,0, 4096);
glMatrixMode (GL_MODELVIEW);
glLoadIdentity();
// Render voxel landscape
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0,1024.f/768.f,1,350.0);
glMatrixMode(GL_MODELVIEW);
// Render 3d models
}
All work, but performance drop dramatically! (from 85 even 20 fps, even if model have less the 200 polygons). I understand, must exist another way to doing this. Any ideas?
The link to voxel source: http://immerse.km.ru/download/project/voxel071.zip
Using ortho and perspective at the same time isn''t your source of slow-down, as pretty much every game does it.
I would imagine your voxel rendering is slow, as it''s not something that 3d cards are good at.
Helpful links:
How To Ask Questions The Smart Way | Google can help with your question | Search MSDN for help with standard C or Windows functions
I would imagine your voxel rendering is slow, as it''s not something that 3d cards are good at.
Helpful links:
How To Ask Questions The Smart Way | Google can help with your question | Search MSDN for help with standard C or Windows functions
Author
My voxel landscape is fully hardware accelerated (it''s psevdo voxel landscape)! It''s possible to adopt voxel for hardware acceleration! Check source!
>>The problem description is – I render voxel based landscape using glOrtho (it’s only one way), but then, I must add 3d models… As far as I understand I must use perspective projection for models…<<
no, not at all.
pick either orthogonal or perspective + render BOTH voxels + 3d models in the same way.
BTW perspective with a small FOV eg 10deg looks very much like orthogonal. ie distance doesnt change scale (that much)
http://uk.geocities.com/sloppyturds/gotterdammerung.html
no, not at all.
pick either orthogonal or perspective + render BOTH voxels + 3d models in the same way.
BTW perspective with a small FOV eg 10deg looks very much like orthogonal. ie distance doesnt change scale (that much)
http://uk.geocities.com/sloppyturds/gotterdammerung.html
Try rendering your voxels OR your poly models, not both, then see where the slowdown is.
Helpful links:
How To Ask Questions The Smart Way | Google can help with your question | Search MSDN for help with standard C or Windows functions
Helpful links:
How To Ask Questions The Smart Way | Google can help with your question | Search MSDN for help with standard C or Windows functions
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