Jump to content

POPs rotations and Bullet


Recommended Posts

post-3767-133157240819_thumb.png

I've gone back to a little side project I started back in 2010, creating a Bullet POP to better understand POPs/HDK/Bullet/C++. I've been able to get it working in H12 (spheresA_bulletPOP.mov), but I'm finding the particles' rotations are going nuts (see the attached file particle_rotation.mov), spinning every which way.

Visualizing the velocity by putting each component ($VX,$VY,$VZ) into each RGB channel respectively, the velocities seem normal (velocity_rgb.mov).

post-3767-13315724797_thumb.png

Coloring the particles with the magnitude of the velocity (see velocity_ramp_scrn.png) also shows some erratic behavior (velocity_ramp.mov).

Is this because POPs have the orientation, rotation, and velocity all driving the single velocity vector, and in bullet they are separate (and rotation is a quaternion)? Or is there a getRot() function (or something like that, which I haven't been able to find) that I can use to set the rotation of each particle from bullet?

My (very rough/unstable) code can be found at: https://github.com/crydalch/houdini-plugins, if you'd like to take a peak.

Thanks so much!

spheresA_bulletPOP.mov

particle_rotation.mov

velocity_rgb.mov

velocity_ramp.mov

Edited by goldleaf
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...