Cg matrices

[captainstan]

I'm trying to transmit to my Cg program the worldlview_matrix, and the projection_matrix, but it doesn't seem to work...
I noticed multiplying the world_matrix and the viewproj_matrix is equivalent to the worldviewproj_matrix, but not to the world_matrix multiplicated by the viewproj_matrix.
Weird isn't it ? Am I (again) missing something ?

[sinbad]

Why don't you just use the autobindings that Ogre gives you?

Matrix multiplication is not commutative, so M * N != N * M.

[captainstan]

inside my shader, I don't want all my vertices to be treated the same, so I need to separate the modelview matrix from the projection matrix.
When you say autobindings, do you mean to use param_named_auto in my material script ? that's what I do but it just doesn't seem to work...
And I take care of the non-commutativity of the matrices, of course.

[sinbad]

You'd need to give us a specific example, we use a variety of auto bindings all the time (separate and combined) and they work fine.

[captainstan]

I'm not on my work PC, so it may not be exactly it..
in my material script, I have my vertex program reference containing

Code: Select all

param_indexed_auto 0 worldview_matrix
param_indexed_auto 4 projection_matrix
param_indexed_auto 8 77 //must be something like that, well it references the morphfactor for terrain shading, anyway it works

and for the moment, in my vertex shader :

Code: Select all

vertout main(float4x4 worldview, 
           float4x4 projection, 
           float morphfactor,
           ...)
{
  position.y = //something with delta and morphfactor
  out_position = mul(worldview, position);
  out_position = mul(projection, out_position);
.....
}

if I pass in world_matrix and viewproj_matrix, it works allright.
I wanna pass the projection matrix separatly, basically because I wanna see if I can obtain some weird effects modifying it.
I've also tried to use param_named_auto with the same results (I don't see anything at all when separating projection from other matrices).

[sinbad]

Ok, it's a bug in the MaterialSerializer, it doesn't have a case statement for projection_matrix. The auto binding is there, and I'm sure it works (since it's derived the same way for viewproj and worldviewproj), it was just missed in the script parser. I'll fix it.

[Edit]Fixed in Hastur, once anon is up to date this should work[/Edit]

[captainstan]

As always, thanks a lot for taking so much time and dig into your code for me. Anyway, it's not my mistake so I'm happy not to feel too dumb with my questions
Don't worry, even genious sometimes forget somethings