rotate object in relation of sth. else

[Penguin]

Probably a simple question:

How do I rotate an object (node3d) in relation to another objects local coordinate system?

For instance, I want to relatively rotate object1 by 1 degree in relation to the z-axis of object2s local coordinate system (roll of 1 degree according to object2).

In another example I want to relatively rotate object1 by 1 degree in relation to the main view (roll of 1 degree according to main view).

[farshizzo]

You can use the matrix.preEuler methods to rotate objects relative to arbitrary coordinate frames. Here is how you would roll object1 relative to object2's coordinate frame:m = object2.getMatrix()
m.preEuler(0,0,1)
object1.setQuat(m.getQuat())You would use similar code to perform the rotation relative to the viewpoint by retrieving the matrix from the viz.MainView object.

Let me know if I misunderstood your question or you need more specific examples.

[Penguin]

This is not exactly what I meant.

For illustrating I attached some screen shots:

Left picture:
Start position. object1 = blue torus, object2 = white torus)

Middle picture:
Your end position. Your code seems to copy the complete orientation of object2 to object1

Right picture:
Desired end position. I want to rotate object1 according to the orientation of object2. Kinda object1.setEuler([0,0,45],viz.REL_LOCAL_of_object2)

[farshizzo]

Ok, it sounds like you want a hierarchical relationship between object1 and object2. In this case you would simply add object1 as a child to object2. When object2 is rotated, object1 will automatically rotate in object2's reference frame. If for some reason you don't want a to use a hierarchical relationship, then here is some code to manually compute the matrix:euler = viz.Matrix.euler(0,0,roll)
m1 = object1.getMatrix()
m2 = object2.getMatrix()

diff = m1 * m2.inverse()

m2new = euler * m2
object2.setQuat(m2new.getQuat())
object1.setMatrix(diff * m2new)

[Gladsomebeast]

Me gusta el code. Porque yo tengo code similar, pero esto code es mas fácil.

También, Penguin usted puede utilizar un objeto Link para esto, si no te gusta hierarchical.

[farshizzo]

Vous êtes fou mec. J'ai comme vous, mais vous êtes fou.

[Penguin]

Thank you, the code works best for me! I only did some minor changes: translating to origin before rotating:


euler = viz.Matrix.euler(0,0,roll)
m1 = object1.getMatrix()
m2 = object2.getMatrix()

m1.setTrans(0,0,0)
m2.setTrans(0,0,0)

diff = m1 * m2.inverse()

m2new = euler * m2
object2.setQuat(m2new.getQuat())
m1new = diff * m2new
m1new.setTrans(object1.getPosition(viz.ABS_GLOBAL) )
object1.setMatrix(m1new)