Microsoft DirectX 8.0 (C++)

Using Volume Textures

The code examples below show the steps required to use a volume texture.

First, specify a custom vertex type that has three texture coordinates for each vertex, as shown in this code example.

struct VOLUMEVERTEX
{
    FLOAT x, y, z;
    DWORD color;
    FLOAT tu, tv, tw;
};

#define D3DFVF_VOLUMEVERTEX (D3DFVF_XYZ|D3DFVF_DIFFUSE|
                             D3DFVF_TEX1|D3DFVF_TEXCOORDSIZE3(0))

Next, fill the vertices with data.

VOLUMEVERTEX g_vVertices[4] =
{
    { 1.0f, 1.0f, 0.0f, 0xffffffff, 1.0f, 1.0f, 0.0f },
    {-1.0f, 1.0f, 0.0f, 0xffffffff, 0.0f, 1.0f, 0.0f },
    { 1.0f,-1.0f, 0.0f, 0xffffffff, 1.0f, 0.0f, 0.0f },
    {-1.0f,-1.0f, 0.0f, 0xffffffff, 0.0f, 0.0f, 0.0f }
};

Now, create a vertex buffer and fill it with data from the vertices.

The next step is to use the IDirect3DDevice8::CreateVolumeTexture method to create a volume texture, as shown in this code example.

LPDIRECT3DVOLUMETEXTURE8 volTexture;

d3dDevice->CreateVolumeTexture( 8, 4, 4, 1, 0, D3DFMT_R8G8B8,
                                D3DPOOL_MANAGED, &volTexture );

Before rendering the primitive, set the current texture to the volume texture created above. The code example below shows the entire rendering process for a strip of triangles.

if( SUCCEEDED( d3dDevice->BeginScene() ) )
{
    // Draw the quad, with the volume texture.
    d3dDevice->SetTexture( 0, pVolumeTexture );
    d3dDevice->SetVertexShader( D3DFVF_VOLUMEVERTEX );
    d3dDevice->SetStreamSource( 0, pVB, sizeof(VOLUMEVERTEX) );
    d3dDevice->DrawPrimitive( D3DPT_TRIANGLESTRIP, 0, 2);

   // End the scene.
   d3dDevice->EndScene();
}