Jump to content
• Advertisement

#### Archived

This topic is now archived and is closed to further replies.

# The Coordinates of a Box

This topic is 6121 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

## Recommended Posts

My question is very simple. If I was to make a primitive of a box(6 sided), and am planning to use D3DPT_TRIANGLELIST to render it, how would I set up the initial D3DVERTEX array before i use device->CreateVertexBuffer(). The answer I''m looking for should(i''d like) to be in the format below. D3DVERTEX aQuad[] = { {-1.0f,-1.0f,-1.0f,0.0f,0.0f}, { 1.0f,-1.0f,-1.0f,1.0f,0.0f}, {-1.0f,-1.0f, 1.0f,0.0f,1.0f}, { 1.0f,-1.0f, 1.0f,1.0f,1.0f} };

#### Share this post

##### Share on other sites
Advertisement
I''d just setup an index buffer & eight vertices...

The coordinates would then be quite easey, you''d just have to extrude your current set of vertices along an axis... (in your case the new 4 would have a positive Y value instead of a negative)

Hope that helps...

-Lonely

#### Share this post

##### Share on other sites
If you use index buffers you can copy the coordinates right out of the SDK Documentation Mesh Cube example:

1.000000;1.000000;-1.000000;, // Vertex 0.
-1.000000;1.000000;-1.000000;, // Vertex 1.
-1.000000;1.000000;1.000000;, // And so on.
1.000000;1.000000;1.000000;,
1.000000;-1.000000;-1.000000;,
-1.000000;-1.000000;-1.000000;,
-1.000000;-1.000000;1.000000;,
1.000000;-1.000000;1.000000;;

These are the indices:
0,1,2;, // Face 0 has three vertices.
0,2,3;, // And so on.
0,4,5;,
0,5,1;,
1,5,6;,
1,6,2;,
2,6,7;,
2,7,3;,
3,7,4;,
3,4,0;,
4,7,6;,
4,6,5;;

#### Share this post

##### Share on other sites
Hi. what is a indices?

#### Share this post

##### Share on other sites
A vertex buffer is a list of 3d Points. An index buffer is a list of offsets into the vertex buffer. The idea is that since many vertices are used for more than one triangle, by using an index buffer, you do not have to specify the same vertex twice. When you use DrawIndexedPrimitive, directX looks up the vertices based on the indices that you provide it.

In the above example, the first 3 indices: 0,1,2 mean draw a triangle from vertex 0 (1.0;1.0;-1.0) to vertex 1 (-1.0;1.0;-1.0) to vertex 2 (-1.0;1.0;1.0).

You can see that 4 triangles reference vertex 0. This means that if you made a triangle list vertex buffer without the index buffer, you would have to specify vertex 0 4 times.

#### Share this post

##### Share on other sites

• Advertisement
• Advertisement

• ### Popular Contributors

1. 1
2. 2
JoeJ
20
3. 3
4. 4
frob
12
5. 5
• Advertisement

• 13
• 19
• 13
• 20
• 13
• ### Forum Statistics

• Total Topics
632194
• Total Posts
3004692

×

## Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!