object rotation from normal vector.

[Stjohn]

I have a point normal that I've extracted from a sequence of obj's dumped out of Maya (don't ask). I want to rotate an object in world space based on the direction of said normal. Currently, I'm barking up the tree involving orienting a matrix to the vector, then doing some sort of crackTransform()-ish operation to get the Euler angles. Problem is, I can't figure out how to get what out of where at which point. This is turning into a No play, makeup and all. Is there some dirt-simple way to do this that I've just missed out on because I spent eight years using Houdini as a front end to a proprietary volume renderer, then another two and a half using it as a front end to the Lighting department?

The only other thing I can think of (and my wrist is already swelling at the prospect) is to do point() and lookat() functions in the object's T and R channels.

Cheers

[symek]

Could you be more specific (about what is not working) or possibly attach simply hip file for an explanation what you're after?

I'm not sure if I understand correctly your problem.

Edited May 6, 2008 by SYmek

[Stjohn]

Could you be more specific (about what is not working) or possibly attach simply hip file for an explanation what you're after?

I'm not sure if I understand correctly your problem.

Simply put, I need to generate Euler rotation angles from a direction vector. I just found the 'vector to rotation' sop here, but I think that's an in-house tool.

[edward]

Take a look at the dihedral() expression function. Note that you need TWO vectors in order to describe the rotation. One of them is which ever axis you want to rotate from (eg. Z-axis) and the other vector is your normal.

[petz]

i don

extract_rot.hipnc