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MARS_999

OpenGL How to reset the identity matrix?

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Ok I am rendering a texture quad and would like to render it at a different place and would like to come back to 0,0,0 and do something else. I have a OpenGL background, but not sure what DX has thats like Push/Pop matrices. I would call LoadIdentity() once and use the push/pop to move around and place objects... Thanks

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D3D as standard doesn't have matrix stacks. D3DX exposes them as an interface (ID3DXMatrixStack), however.

To set the identity matrix, you just call:
D3DXMATRIX mat;
D3DXMatrixIdentity(&mat);
pDevice->SetTransform(D3DTS_WORLD, &mat);
Everything from now on will be rendered using an identity matrix.

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Just to add what Steve said... The software design/architectural concepts behind OpenGL's matrices are different to Direct3D's. The end result is pretty much the same (once you've compensated for LH/RH) but the code is fairly different.

The biggest problem I had when I tried OpenGL was getting my head around how to use it's matrix system.

Might be a good idea to try and get used to the "D3D Way" rather than program D3D like you're programming OpenGL.

hth
Jack

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