How to set custom camera Matrix

Coding Python Support
1

Sort of newbie question:

I would like to setup camera with my own (Dimetric) projection.

From the code I figured out that for camera I can set type: Perspective or Orthographic and corresponding params (lens shift_x shift_y clip_start clip_end or ortho_scale ), but this is not what I need for Dimetric projection I would compute camera matrix myself and provide to camera.

There is mathutils.Matrix.OrthoProjection which can provide me with matrix, I can code something the same for Dimetric projection, the question remains - how to set this matrix to Camera. Or for what reason mathutils.Matrix.OrthoProjection exists?

2

Do I get it right that I need to change C code then compile Blender myselft to get another sort of camera in Blender?

3

For anyone interested dimetric and trimetric projection ( see http://www.significant-bits.com/a-laymans-guide-to-projection-in-videogames ) (for preview at least, not in render though ) could be achieved by having custom wmOrtho something like:

void wmOrthoCustom(float x1, float x2, float y1, float y2, float n, float f,float scalex,float scaley,float scalez)
{

float l=x1/*x1*/, r=x2, b=y1, t=y2/*y1*/ , f_=f/*f*/ , n_=n/*n*/; //n - ear f - far r - right 

glMatrixMode(GL_PROJECTION);
glLoadIdentity();


orig_projmat[0]=scalex*(2./(r-l));  orig_projmat[4]=0;     orig_projmat[8] =0;         orig_projmat[12]=-(r+l)/(r-l);
orig_projmat[1]=0;      orig_projmat[5]=scaley*2/(t-b);    orig_projmat[9] =0;         orig_projmat[13]=-(t+b)/(t-b);
orig_projmat[2]=0;      orig_projmat[6]=0;      orig_projmat[10]=scalez*(-2/(f-n));    orig_projmat[14]=-(f+n)/(f-n);
orig_projmat[3]=0;      orig_projmat[7]=0;      orig_projmat[11]=0;                    orig_projmat[15]=1;

glLoadMatrixf(orig_projmat);

glMatrixMode(GL_MODELVIEW);

}

4

can this be done with python or only C ++?

and it cannot be used for the render output ?

did you check if this can be done in YAFARAY for instance ?

salutations

5

It cannot be done with Python currently ( though I made hackish ( just to take a look at the result ) export to python to use this capability from script ) due to that no other than Ortho or Perspective matrix is known to python.

as for render - just the same projection matrix should be inserted somewhere in render output and it can be done in YAFARAY, again, after tweaking projection matrix.

6

may be you could ask on IRC if there are any possibilities ?
who knows there might already be a solution for this !
in any case it would be interesting to have this feature in 2.5 !

good luck
happy 2.5

7

I will drop a line to dev list

8

hello, i would like to know hwo you apple your wmOrthoCustom function to a Camera in the 3D scene?with python?

9

can you put that may be in a small script using a sinple panel like too pro and give 2 choices for dimetric and trimetric
as a script example

at least other people might be able to do it faster !

nice to know there is a way here

thanks happy 2.5