Absolute/Relative Movement

Posted By: Carlos3DGS

Absolute/Relative Movement - 05/18/09 10:49

Ok, so at first it seems quite simple. relative movement is movement oriented to the model's position/angles, and absolute movement is on the world's x,y,z axis

For movement it works like a charm, and i have correctly used relative and absolute movement many times.
My problem is with absolute rotation of a model. No matter how i do it I always get relative (oriented to model axis) tilt/roll rotations! Even when I edit the tilt/roll parameters of a model directly (with no function) it will also use relative (oriented to model axis) rotation...

the only value that seems to use absolute rotation (oriented to world's axis) when editing directly is pan.
cry

How do I change a model's tilt/roll angles in absolute values?
(I dont want the model to move, just rotate at the model's current position but in the directions of the world axis's tilt/roll and NOT the model's axis)
Posted By: Germanunkol

Re: Absolute/Relative Movement - 05/18/09 19:32

maybe what you're seeing is that the angleschange in weird ways if tilt has reached 90 and goes above it.
Have you tried small values only?
For example: add an entity at 0,0,0 and add 10 to its pan every time you hit key_cul and 10 to its tilt every time you hit key_cuu, then display the new entity.pan and .tilt on the screen.
They should be correct until you reach large values (above 90) and should be absolute.
Posted By: Carlos3DGS

Re: Absolute/Relative Movement - 05/18/09 21:18

No,that is not what I mean.
Mabe I didn't explain it well. Here is a picture to better explain what I mean.

I can never get absolute rotaition (relative to world axis no matter where the model is facing).
Even when I do not use any functions (I edit the tilt/roll directly) it always does relative rotation (rotation oriented to model's axis)

Does anyone know how i can get tilt/roll to do absolute rotation?
Posted By: Pappenheimer

Re: Absolute/Relative Movement - 05/18/09 21:27

Do you mean a similar problem to this?

Transform Obejct independant of Orientation
Posted By: KiwiBoy

Re: Absolute/Relative Movement - 05/18/09 21:28

A while ago some one suggested quaternions, whatever that is, as the tilt is subject to gimbol lock.

Currently jcl is writing a solution to incorporate within the next update, that should sort it out. I recall reading this not too long ago actually.
Posted By: Carlos3DGS

Re: Absolute/Relative Movement - 05/18/09 22:03

@Pappenheimer: Similar but not exactly. His problem is how to do absolute scaling after his model is rotated. My problem is how to do absolute rotation after my model is rotated.
Do you know how I can contact the person that helped him? Mabe he can help me also, my problem seems more simple.

@KiwiBoy: I did not understand what you were talking about but it sounds promising, please tell me more about that.
Posted By: Pappenheimer

Re: Absolute/Relative Movement - 05/18/09 22:28

FlorianP is the Nickname in this forums, don't know more about him.
Posted By: KiwiBoy

Re: Absolute/Relative Movement - 05/19/09 07:19

Sorry dont know anything anout it really.
Did you try incorporating abs and rel to the equation?
© 2023 lite-C Forums