hmm, ok..dont pay any attention on this.. seems to be siilly words i spoke, just saw that thing at an example and got confused, too.

i am not completely sure but i think wolfgang engel's per pixel lighting examples use a transposed world matrix. maybe this would be useful?

I think access to the transformation matrices could make sense in some situations. As game developer I know which objects are fixed and which are not. For a fixed object I need only one time the inverse worldmatrix, in a loop I would transform the eyepositon to objectspace and set them in the entity or material skills which are used as constant values (one calculation per model). In vertexshader the transformation would be calculated for each vertex, which could be expensive depending on the number of vertices.

As you set the worldmatrix in constants which are vectors of four floats the worldmatrix we get from the engine is already transposed.

oh! i see! some of this matrices stuff still confuses me...

Maybe the following try to explain it could help you.

Code:

---

  .



Multiply a vector with a Matrix:



                       M11 M12 M13

[x’ y’ z’] =[x y z] *  M21 M22 M23

                       M31 M32 M33



/////////////////////////////////////////////////////

 x’=(x*M11)+(y*M21)+(z*M31)

 y’=(x*M12)+(y*M22)+(z*M32)

 z’=(x*M13)+(y*M23)+(z*M33)

/////////////////////////////////////////////////////

the Matrix set as it is in constants:



c0=(M11,M12,M13)

c1=(M21,M22,M23)

c3=(M31,M32,M33)

/////////////////////////////////////////////////////////

would not lead to the expected solution in the dot product:



x’=(x*M11)+(y*M12)+(z*M13)

y’=(x*M21)+(y*M22)+(z*M23)

z’=(x*M31)+(y*M32)+(z*M33)    

/////////////////////////////////////////////////////

Transposing a Matrix means to exchange the rows with the columns:



    M11 M12 M13	    	               M11 M21 M31

A = M21 M22 M23       A transposed =   M12 M22 M32

    M31 M32 M33        		       M13 M23 M33

//////////////////////////////////////////////////////////////////////////////////

Set the transposed Matrix in constants:



c0=(M11,M21,M31)

c1=(M12,M22,M32)

c2=(M13,M23,M33)

//////////////////////////////////////////////////////////////////////////////////

Now we have the same result as  multiplication a vector with a matrix.



x’=(x*M11)+(y*M21)+(z*M31)

y’=(x*M12)+(y*M22)+(z*M32)

z’=(x*M13)+(y*M23)+(z*M33)

---

This explanation is not perfect, but I think it could be helpful.

The stuff is more confusing, if you don’t know how Direct3D deals with those matrices and in a tutorial this is required like in the tuts from Wolfgang Engel.

Some information from the D3DCaps8 structure would be useful, like the shader versions and max simultaneous texture.

its me again. i found the use of a cv_color(maybe that is a colorvector) in the toonshading example of the NVeffectsbrowser.

and i came across many times the "eyepoint" - what vector is that?

mss, thanks for the explanation!

...
i guess the eyepoint is the view position. you can get it from the worldview matrix.

VertexShaderConstant[8]=<matWorldView>;
c10 is the view position then. (i guess in modelspace)