Applications can apply perspective correction to textures to make them fit properly onto primitives that diminish in size as they get farther away from the viewer. See D3DRENDERSTATE_TEXTUREPERSPECTIVE.

The following code fragment illustrates the process of enabling texture perspective correction:

// This code fragment assumes that lpD3DDevice is a valid pointer to
// an IDirect3DDevice7 interface.
 
// Enable texture perspective.
lpD3DDevice7->SetRenderState(D3DRENDERSTATE_TEXTUREPERSPECTIVE, 
                             TRUE);

For the IDirect3DDevice3 and IDirect3DDevice7 interfaces, the default value is TRUE to enable perspective correct texture mapping. For earlier interfaces, the default is FALSE. Note that many 3-D adapters apply texture perspective correction unconditionally. Perspective correction must be enabled to use w-based fog, and w-buffers. For more information, see Eye-relative vs. Z-Based Depth in the Fog section, and Enabling Depth Buffering in the Depth Buffers section.

Applications can apply perspective correction to textures to make them fit properly onto primitives that diminish in size as they get farther away from the viewer. See D3DRENDERSTATE_TEXTUREPERSPECTIVE.

The following code fragment illustrates the process of enabling texture perspective correction:

' This code fragment assumes that d3dD3DDevice is a valid reference to
' a Direct3DDevice7 object.
 
' Enable texture perspective.
Call d3dDevice7.SetRenderState(D3DRENDERSTATE_TEXTUREPERSPECTIVE, _ 
                               True)

The default value is True to enable perspective correct texture mapping.

Note that many 3-D adapters apply texture perspective correction unconditionally. Perspective correction must be enabled to use w-based fog, and w-buffers. For more information, see Eye-relative vs. Z-Based Depth in the Fog section, and Enabling Depth Buffering in the Depth Buffers section.