Quote:Original post by Shael

Quote:Original post by simotix
Maybe I am not explaining it correctly, but I do not understand what is going on here

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That is my main concern, understanding that code. I do not understand why those values were chosen, what they are doing there and how they can be defined. That is what I am looking to be answered.

Those values are simply the position of the "light" that is projecting the texture. Try to think of projective texturing as if it were a film projector projecting a film onto a canvas. You need to specify the position of this projector, the direction it will project images, and its field of view.

Theres no reason why you can't change those values (60,90,0), they simply define the projector to be 60 units to the right and 90 units up from the origin, and the origin is the position the projector is facing to place the projected image.

One thing to note, make sure "objectTransform" is the identity matrix.

Quote:Original post by NiGoea
HAha what is that :)

Anyway, if you have not yet understood what D3DXMatrixLookAtLH and D3DXMatrixPerspectiveFovLH do, maybe you should start with something simpler than Projective Texture Mapping. Like setting a camera and move it around the scene.

I've learnt projective TMap while studying shadow maps. Things are not so difficul as they seem. Basically:
- for each pixel, obtain its screen space position
- by means of a matrix mul, compute its light space position
- project that pixel using the light projection matrix
- now you have clip space coordinates. Convert those to texture space coordinates ( * 0.5 + 0.5)
- now you can access to your goddamned texture :)

(stop pasting thousand of lines of code...)