I am using 2 TransformedTextured vertex buffers in my scene:
1 for the background
1 prop
I assumed that the Z value was a value between 0 and 1; where 1.0 was the back of the scene. This works well for the background, so with this thought, I also assumed then that z=0.5 would place the plane halfway between the front clipping plane. But this does not appear to be the case. The Z value definitely has an impact on the plane's position between the front and back clipping planes, but does not behave as I would have expected.
Can anyone shed some light as to how the Z value of a TransformedTextured buffer is used

TransformedTextured depth (Z) values
R_oo_T
casgo
This value gets divided by w then it is stored directly in your depth buffer...
Sorry, but that's a false answer... In the case of TransformedTextured, the z-value you specify is directly used in z-testing and will be stored in the depth buffer if the z-test succeeds...
The w-divide happens for vertices that use the T&L pipeline or vertex shaders. So in a vertex shader, you output normalized values that will be subsequently divided by w and then scaled to the viewport's size...
Sorry for the confusion...
Big-O