Simple Question.

MrNeedHelp · 2003-06-09T12:41:58

I have a vertex buffer and an index buffer set up . Now , i want to render the triangles using an offset . I mean , if my index buffer is like this : 0 , 1 , 2 , 3 , 1 , 2 How do i render only the second triangle (that indices 3 , 1 , 2) specify in my DrawIndexedPrimitive Call ? I know this is just something as simple as setting an offset parameter but the parameter naming is not very helpful , nor the 1 line sdk explanation . Thx

Graphics and GPU Programming Programming

Started by MrNeedHelp June 05, 2003 08:39 AM

22 comments, last by MrNeedHelp 20 years, 10 months ago

MrNeedHelp

122

Author

June 08, 2003 07:34 PM

some help pls , i spent 2 days on this!

[edited by - MrNeedHelp on June 9, 2003 7:24:36 AM]

thanks

MrNeedHelp

122

Author

June 09, 2003 06:29 AM

AnyOne ?

thanks

Anonymous

June 09, 2003 06:46 AM

Hi, did you manage to fix this?

I think the problem is in the parameters you are passing in the DIP call.

In the second call, if you look at the MinIndex and NumVertices values you''re passing in, you''re telling D3D that you are using a range of vertices from 0 (MinIndex) to 11 (NumVertices - 1). In your index buffer, you then reference vertex 24 which is outside of this range (0-11), hence D3D reporting that its come across an invalid index entry in the stream.

If your''re using the first 24 vertices for the first call, the next 12 for the second call and the last 12 for the third call, you want to use:

->DrawIndexPrimitive(D3DPT_TRIANGLELIST,0,0,24,0,16);
->DrawIndexedPrimitive(D3DPT_TRIANGLELIST,0,24,12,48,14);
->DrawIndexedPrimitive(D3DPT_TRIANGLELIST,0,36,12,90,14);

At least I think thats it! Apologies in advance if I''ve made a mistake here...