I have a number of objects (points) in a 3D space. I need to rotate this space using euler angles (or equivilent) and place it in another coordinate system. (ie i start with objects placed within the confines of a cylinder aligned with the z axis, and after rotation have a cylinder of objects at some chosen angle and orientation compaired to the z' axis in a larger cartesian space.)(adsbygoogle = window.adsbygoogle || []).push({});

Each one of these points in given an initial velocity, which must be kept during the rotations. ie if a point initialy has a velocity towards the center of the cylinder (the z axis before rotation), the velocity after rotation must be of the same magnitude and towards the center of the cylinder (ie NOT the new z' axis).

I can easily rotate the points, howoever i cannot work out how to rotate the velocity vectors about the origin with the points in order to keep the velocities true. can anyone suggest how i could do this please?

in case this is not clear, i shall give an example of one point

say i have a point which is on the point on the x axis with a vector representing its velocity pointing towards the z axis. a rotation in the xz plane of 90degrees would put the point on the z axis with the velocity pointing towards the xy plane.

hope this didnt make this more complicated. the important thing is not the velocity, it is simply a euler rotation of a point (x1,y1,z1) which has attached a vector (vx1, vy1, vz1) which starts at (x1,y1,z1).

what i need in the end is the point in the new coordinate system and the velocity vector associated with it.

can this be done and how?

thanks for reading all this

jimbo

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# Euler rotation of objects with velocity vectors

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