Vector to Screen Coords

PLEASE HELP ME??!!!

I cannot figure this out.

struct D3DVECTOR
{
  float x;
  float y;
  float z;
};

struct D3DVERTEX
{
  float x;
  float y;
  float z;
  float nx;
  float ny;
  float nz;
  float tu;
  float tv;
};

Just copy the coordinates from your D3DVECTOR to the x,y, and z components in D3DVERTEX. Leave the rest of the attributes zero. Now you should be able to render the model, though it will be black since Direct3D doesn''t have enough information to light the vertices. You need to set the normals to have correct lighting. Either you get the normals from the file or you compute it.

You can also skip copying the coordinates completely and render from you array of D3DVECTORs directly. You do this by supplying D3DFVF_XYZ instead of D3DFVF_VERTEX as dwVertexTypeDesc in DrawPrimitive() or DrawIndexedPrimitive().



- WitchLord

Yea that normals thing. What is that and how do i calculate them. What are they. I read alot about them.

Also does anyone have the code to draw a simple cube in d3d NOT using the d3dframe utility lib. I need the real code

Thanx

You can compute the normal for a triangle composed of three vectors (V1,V2,V3) like this:

D3DVECTOR N = Normalize(CrossProduct(V2-V1, V3-V1));

Then you can for each vertex average the normals of the triangles connected to the vertex to produce the vertex normal.

The normal is a vector that describes to the lighting functions in which direction the surface is facing at the corresponding position.

Sorry, I don''t have time right now to write the code for rendering a cube. Rendering the cube without using d3dframe.lib is done the same way as with d3dframe.lib. The only thing d3dframe.lib helps you with is the initialization, and some other tedious work.



- WitchLord