I use the following code to plax a flat box on the screen. D3DVECTOR p1 = D3DVECTOR( -.5f, -.5f,0); D3DVECTOR p2 = D3DVECTOR( .5f, -.5f,0); D3DVECTOR p3 = D3DVECTOR( .5f, .5f,0); D3DVECTOR p4 = D3DVECTOR( -.5f, .5f,0); But only one triangle shows up. When I rotate it along the y axis, I see the other triangle on the ''back'' of the first. I have been staring at this code forever and I''m sure that I missed something ignorantly small.. BTW - I render with a D3DPT_TRIANGLESTRIP. Thanks

D3D culls counterclockwise triangles, and you have your vectors defined in counterclockwise order. it should be like this:

D3DVECTOR p1 = D3DVECTOR( -.5f, -.5f,0);
D3DVECTOR p2 = D3DVECTOR( -.5f, .5f,0);
D3DVECTOR p3 = D3DVECTOR( .5f, .5f,0);
D3DVECTOR p4 = D3DVECTOR( .5f, -.5f,0);

or you could change the way d3d does culling by doing this:

IDirect3DDevice3->SetRenderState(D3DRENDERSTATE_CULLMODE, D3DCULL_CW);

(D3DCULL_CCW is default)

i''d suggest the first way though.