Set rotation by 3x3 matrix?

Reply to Set rotation by 3x3 matrix? on Tue, 27 Apr 2010 11:12:43 GMT

sonsofsol — Tue, 27 Apr 2010 11:12:43 GMT

i have a tripod of 3 vectors, all 90deg to eachother.
x1,x2,x3 ---> viewvector
y1,y2,y3 ---> crossproduct1 of viewv.
z1,z2,z3 ---> crossproduct2 of viewv.
how can i set an objects rotation to this new rotation matrix?
i have a halfbaked solution with rotateXYZ that computes angles, but i guess it should be possible to override the rotation matrix somehow, wich would be much nicer.
thanks for help in advance.

Reply to Set rotation by 3x3 matrix? on Thu, 06 May 2010 16:12:29 GMT

sonsofsol — Thu, 06 May 2010 16:12:29 GMT

so i found out that its possible to set a modelview matrix with glLoadMarix.
and that it looks like this
http://wiki.delphigl.com/index.php/Matrix#Aufbau_einer_OpenGL-Matrix

| 0 4 8 12 |
| 1 5 9 13 |
| 2 6 10 14 |
| 3 7 11 15 |
+- -+

where (i guess...)
0 = front X
1 = front Y
2 = front Z
3 = 0
4 = right X
5 = right Y
6 = right Z
7 = 0
8 = up X
9 = up Y
10 = up Z
11 = 0
12 = pos X
13 = pos Y
14 = pos Z
15 = 1

but i still dont have any idea how to patch it...
i hope someone can help me

Reply to Set rotation by 3x3 matrix? on Thu, 06 May 2010 16:49:17 GMT

sonsofsol — Thu, 06 May 2010 16:49:17 GMT

GEMglLoadMatrix seems to be not existing...
somebody from OGL forum sent me this code

var Matrix: array[0..3] of array[0..3] of single;
begin
glPushMatrix;
Matrix:= [ [ Right.x, Right.y, Right.z, 0],
[ Up.x, Up.y, Up.z, 0],
[ Front.x, Front.y, Front.z, 0],
[ 0, 0, 0, 1] ];
InvertMatrix(Matrix);
glMultMatrixf(@Matrix);

//Billboards zeichnen;

glPopMatrix;
end;

GEMglPushMatrix exists, but i dont get a second inlet to feed it the matrix
and i have no idea how to do it.
Any ideas?

Reply to Set rotation by 3x3 matrix? on Wed, 12 May 2010 11:00:15 GMT

sonsofsol — Wed, 12 May 2010 11:00:15 GMT

its so simple, sometimes...

http://www.pdpatchrepo.info/hurleur/facing.pd