Part of the Khronos Group
OpenGL.org

The Industry's Foundation for High Performance Graphics

from games to virtual reality, mobile phones to supercomputers

Search:

Type: Posts; User: MichaelA

Search: Search took 0.00 seconds.

  1. Replies
    6
    Views
    2,700

    Re: Inverse Orthogonal Matrix

    Yes the matrix is orthonormal, I get those terms confused. I do not use scaling at all.
    I cannot thank you enough for this information, I knew it was possible, I studied matrices in Linear Algebra,...
  2. Replies
    6
    Views
    2,700

    Re: Inverse Orthogonal Matrix

    Thanks for your help, just one more question to clear it up for me a bit better.
    So to get my inverse matrix, I separate the rotation and translation into their own matrices, transpose the rotation...
  3. Replies
    6
    Views
    2,700

    Re: Inverse Orthogonal Matrix

    Thanks a lot, very helpful!
  4. Replies
    6
    Views
    2,700

    Re: Inverse Orthogonal Matrix

    Just wanted to clarify:

    If the first mat is M1 and its inverse, the second mat, is M1^-1 and I want to multiply M1^-1 by another matrix M2 to get the relative transform between M1 and M2, will I...
  5. Replies
    1
    Views
    810

    Re: How do I code a spline path?

    There is a lib called SGcore - there is a demo version available for download. It contains spline functions. Just keep in mind you need at least 3 points to define a spline using that lib.
  6. Replies
    6
    Views
    2,700

    Inverse Orthogonal Matrix

    From what I understand (please correct if I'm wrong) if I have an orthogonal 4x4 matrix that contains no scaling and only rotation and translation, I can obtain the inverse matrix by transposing the...
  7. Replies
    3
    Views
    1,131

    Re: How to remove material from Solids?

    For anyone who is interested, after an exhaustive web search, I found a most useful solids modelling library that works with OpenGL and I am sure other rendering engines. sgCore by Geometros.
    I...
  8. Replies
    3
    Views
    1,131

    Re: How to remove material from Solids?

    Thanks, CSG has now been added to my search terms.
    Cheers!
  9. Replies
    3
    Views
    1,131

    How to remove material from Solids?

    I have been given a project to work on that renders an object after it has intersected with another object, i.e one object "removes material" from another object. For instance, a drill enters a piece...
  10. Re: [SOLVED] How to swap Y and Z axes in a matrix?

    I forgot to add that your x-axis will be reversed after the second rotation.
  11. Re: [SOLVED] How to swap Y and Z axes in a matrix?

    You would rotate around the x-axis exactly positive 90 degrees (pi/2 radians), the positive z-axis will now be where the positive y-axis was, but the negative y-axis will be where the positive z-axis...
  12. Replies
    5
    Views
    1,902

    Re: Matrix Rotations

    I would like to help with this. Can you provide the actual code you are using inside your Multiply function, and also the snippet of code that surrounds the function call? I would like to see how...
  13. Replies
    5
    Views
    1,955

    Re: Acceleration Problem

    Thanks very much for your help with this everyone. I had a feeling I was going to run into a problem with this.

    Just to give a better idea about what I'm trying to do, my application is a machine...
  14. Replies
    5
    Views
    1,955

    Acceleration Problem

    Hello again everyone,

    I have worked out an acceleration profile for a special motion application that ends up looking like this:

    d = (t + sin t)/2

    (I took the integral of (1 - cos t)/2) so...
  15. Replies
    12
    Views
    4,052

    Re: Rotation Parallel to Vector

    OK, we started with this

    float az = atan2 (dy, dx) * RADDEG;
    float el = asin (dz / length ) * RADDEG;

    glPushMatrix ();
    glRotatef ( az, 0,0,1);
    glRotatef...
  16. Replies
    12
    Views
    4,052

    Re: Rotation Parallel to Vector

    Thanks very much! I understand, I will put it to good use very soon.

    Thanks again,
    Mike
  17. Replies
    12
    Views
    4,052

    Re: Rotation Parallel to Vector

    I think the problem is related to my original question. I want to draw a gluCylinder, which defaults to being drawn with its height along the Z-axis starting at the origin. Sorry, I forgot to...
  18. Replies
    12
    Views
    4,052

    Re: Rotation Parallel to Vector

    MaxH,

    Thanks very much, I am going to try both your method and the one suggested by KjuEnnDee and see how it goes.

    My WorldUp vector is Z so I will modify accordingly. It took me a few...
  19. Replies
    12
    Views
    4,052

    Re: Rotation Parallel to Vector

    KjuEnnDee, thanks for the reply.

    So are you saying I build my own rotation matrix and then load that into the MODELVIEW matrix?

    If so then I will try the math approach you suggested.
    ...
  20. Replies
    12
    Views
    4,052

    Rotation Parallel to Vector

    Hi everyone. The problem is as follows:

    I have a line drawn between two vertices and I would like to rotate a gluCylinder so that it is pointing in the same direction (parallel to the line).
    I...
Results 1 to 20 of 20