Dear. I think this question is asked for many many times, but I still have something un-clear in implementing the hardware shadow map by Nvidia hardware... The configuration I am using is as follow. I am using DirectX9 SDK, with a piece of Nvidia GeForce4 hardware, and I am now able to generate a depthstencil texture. And i am using VS1.4 and PS1.4 for both case. The above config is fixed, as I cannot use lower VS and PS (not enough texture registers) and higher VS and PS (need to support as much card as possible) I have the following questions: 1> Do i need to set the depthStencil Texture as Texture zero, or I canset it as any texture stage I want. I have this question, because the documentation "GPU Programming Guide" by Nvidia said (seems to be) that, it should be located in texture unit 0... 2> For PS_1_4, how can I perform a "projected texture fetch" in the shader? as the above documentation mentioned, if using 1.1-1.3, the action can be set by setting sampler stage. If using 2.0 or above, I can find the exact texture call (texProj). But in 1.4, the only call I can find is "texld r0, t0_dw.xyw", but it seems not work (after I have used it). Is there ant tick I need to take care, or is there any detailed documentation available? thx thx thx