I’m trying to emit particles that move at a slow constant speed using PSA velocity so I can have have them aligned to the direction that they move. Using the sphere module with ‘surface’ and ‘velocity’ checked, and a velocity of say 0.1 - 0.9 will cause the particles to align properly however they will stretch on y axis, usually scaling the y axis towards 0. Is there a way to normalize the input velocity to prevent the particles from scaling at slow speeds?
This also occurs in other circumstances where a particle travels at a slow rate, IE using vel/life or drag to slow down a particle.
that shouldnt happen unless you use a velocity/size module.
it can also happen if you have a random innitial size module, which randoms between min/max on the X and Y separately, this could also result in a scaling issue.
worst case, make a video/few images showing the more important modules.
Thanks for your reply. I’m still seeing the stretching at low velocities. I was seeing some jitter as well but that only occurs in cascade and the editor.
Here’s a video showing the issue I’m seeing. I set the particle size to constant x=25 y=100, I’m emitting particles from a sphere source in all directions. When I set the velocity to a low number < 1 the particles will scale on the y axis. In the video I turn on drag to exaggerate the what I’m seeing.
One other thing I’m seeing: switching the TypeData to GPU Particles will fix the issue (particles will retain their initial size no matter the velocity). Unfortunately I can’t use GPU particles for my project, so I’m right back at the original issue
It seems that particles stop squashing and stretching at velocities greater than 10. Any slower and the particles will scale on the y axis.
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I was seeing this issue when messing with slow motion. Slowing time affects the velocity too. A particle with 10 velocity at normal playback speed will have a velocity of 1 at 10% playback speed and thus appear squashed.
So don’t use velocities lower than 10 if you don’t want your velocity-aligned particles to change size. More of a workaround than an answer. If you want to use lower velocities, you have to compensate by increasing the y size and then make sure the playback speed doesn’t change.
