Archived

This topic is now archived and is closed to further replies.

Rotation Matrix

This topic is 5836 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

Recommended Posts

Hi, how do i create a axis-angle rotation matrix in detail????

Share on other sites
glRotatef(angle, 1.0, 0, 0)
the above rotation will multiply the proper rotation matrix automatically by the current matrix. The order in which you perform transformations will drastically vary in the final effect. Think about it. Say your program is only drawing a spere at the grand fixed origin, where the camera rests by default(0,0,0). In your display function, if you wanted to rotate a sphere and then translate it. you''d do this:
void display(void){	glClear(GL_COLOR_BUFFER_BIT);	glColor3f(1.0, 1.0, 1.0);			glPushMatrix();	glTranslatef(-3.0, 0, 0);	glRotatef((GLfloat) ???angle, 0, 1.0, 0);	glutWireSphere(0.05f, 6, 4);	glPopMatrix();        .        .        .[/CODE]^^^^^^^^^The above will first rotate an abstract local origin about the origin, thin will move it "-3" along the x. Done backwards, this would result in the sphere orbiting around the grand origin rather than rotating about it. The normal vectorfor rotation (0,1,0) just says to rotate around the y axis.if it had been(0,0,0), around what would it rotate?!?!?!*notice how rotate comes after translate, it''s because the Matrix multiplication order is backwards, somewhat.i.e. T(R*Sphere)for t = trans, r = rotation***very important to grasp!

Share on other sites
well, a rotation matrix that rotate around the Z axis

cos( ang ) -sin( ang ) 0
sin( ang ) cos( ang ) 0
0 0 1

around Y axis

cos( ang ) 0 -sin( ang )
0 1 0
sin( ang ) 0 cos( ang )

and around X axis

1 0 0
0 cos( ang ) -sin( ang )
0 sin( ang ) cos( ang )

i hope this was that you are looking for.

Share on other sites
http://www.flipcode.com/documents/matrfaq.html

Share on other sites
given angle
and a direction (x, y, z) (where ||(x, y, z)|| = 1)

then the matrix is
<pre>
xx * (1 - c) + c xy * (1- c) - zs xz * (1 - c) + ys 0
yx * (1 - c) + zs yy * (1 - c) + c yz * (1 - c) - xs 0
zx * (1 - c) - ys zy * (1 - c) + xs zz * (1 - c) + c 0
0 0 0 1
</pre>

where c = cos(angle)
where s = sin(angle)

1. 1
2. 2
3. 3
4. 4
frob
15
5. 5

• 16
• 12
• 20
• 12
• 19
• Forum Statistics

• Total Topics
632164
• Total Posts
3004520

×

Important Information

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!