View Full Version : speed by surface

11 November 2007, 02:53 PM
Ok, I have two questions. First, I need to make my particles follow the surface of my (so called) asteroid, but they just won't do it and I think I am missing something, because I've seen this happen, just can't remember where. Here is a screenshot of the surface: (
(It's pretty crude on the screen, but when I render I pump up the iterations to 6 or 7) I have tracked a few particles with my eyes and it's pretty obvious that they don't follow the surface and that's what I'm trying to do :)

The second thing is just a slight improvement... I need to make the particles follow the surface with an offset in the geometry's normal direction, because when I put the iterations to 7 and all the detail comes out (lots of small bumps and so forth..) it will cover most of the particles I think.

So if anyone could help me on this gets a totally free beer :)

11 November 2007, 04:35 PM
That is very difficult to accurately achieve with standard PFlow. It is infact why there is the Lock/Bond test in PFTools Box1, which does this with absolute ease :)
Otherwise, the Speed by Surface, set to Parallel to Surface, and Control Speed Continuously is the best you have.

11 November 2007, 06:20 PM
Assuming you have a position object... how about ticking the lock on emiter and the animated shape ? There's also a surface offset setting on that... but if you want the particles to be animated while the asteroid is moving... that's a completely different thing!

11 November 2007, 09:16 PM
In the ideal case the asteroid will be travelling trough space and particles will be spawning on it's surface with a slight offset. Some of the particles will be affected by two turbulent wind forces and the other particles will be crawling on the asteroid's surface while the asteroid is moving. It's what seems most physically probable to me... I hope you got my point.
@Kameleon - I will try this and post a feedback, thanks!

P.S. Is it normal to have a really incredible drawback in the performance when I check that "control speed continiously" thing? I mean my PC isn't the best market can offer but... come on I didn't have that even with 50k particles in viewport. Is it normal or it's just me?

P.S. 2 on the image I have uploaded you can see the SDeflector that determines which particles to use the speed by surface operator.

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11 November 2007, 09:16 PM
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