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View Full Version : best way to do sand blowing across a desert??


KillMe
08-19-2005, 09:40 PM
its all in the title i'm trying to create a desert but by its very nature it looks dead so i thought some sand blowing across the dunes would help lift it abit but i'm struggling as to how best to do this effect - any tips for creating a nice particle effect would be appriated

jsut so you know its not the hv's spites etc i need help with its the particles

ericsmith
08-19-2005, 10:58 PM
This may not be exactly the answer you're looking for, but you may want to look at creating a bunch of transperent planes with an animated procedural texture. The right gradient falloffs could give you a real nice effect.

Eric

Nu Visual Science
08-20-2005, 12:19 AM
Well the key here is to use Winds, There are various differing winds to try in LW and you will get exactly what you want.
I only know this because somebody asked about a river effect yesterday so i experimented with wind and cloth and got a cool looking river, Dont forget to experiment with the velocity settings and stuff bringing them right down and so on, You should be able to get what you want.

Just remember thoiugh not to force the particles, Let the wind do all the work ;)

blaqDeaph
08-20-2005, 09:03 AM
This may not be exactly the answer you're looking for, but you may want to look at creating a bunch of transperent planes with an animated procedural texture. The right gradient falloffs could give you a real nice effect.

Eric

This would depend on how much control he wants with the particles, whether or not they collide with objects (like swirl around rocks etc).

I'd recommend using particles, and playing with collisions. Basically whack in an emitter, and let the wind blow away. Experiment with the various modes of wind, and textures of wind. The LW help menu has a brief explaination of what the modes and settings in the wind do.

kevman3d
08-20-2005, 10:12 AM
Personally, I'd consider using another copy of the landscape object, slightly above the surface of the other, and use fractals as already mentioned. I used that approach to get fine dust blowing across a dry river bed effect a while ago now... Sand I can't see being much different...

On the other hand, I would suggest the easiest way to get some kind of PFX working would be to add an emitter to the landscape so that the pfx get generated on the surface, with some initial velocity, vibration and use the surface as a 'stick' collision as well... You can chuck in some wind effectors if you need swirling, etc...

Something else you can try - leave child particles behind the initial 'sand' ones. Use the HV 'particle size' to expand the sprite (to simulate the sand dissipating) and fade out at the same time... You can also use small Hypertextures in your sprites, and apply 'Velocity Translate' to move the Hypertexture with the speed of the particles to get that extra 'sub particle' motion to your moving sand...

Good luck.

KillMe
08-20-2005, 12:49 PM
i've never had much sucess with using geometry with fractals on it - somehow it never looks right when i try =/ must be somethign i'm missing in the technique

as for partcles etc never been very good with wind =/ pah i should stick to modeling - i guess i'll try experiemtnign somemore with the wind types etc never thought to look up the help to learn abit more about them which is a good idea

Jarrede
08-20-2005, 01:11 PM
i've never had much sucess with using geometry with fractals on it - somehow it never looks right when i try =/ must be somethign i'm missing in the technique

as for partcles etc never been very good with wind =/ pah i should stick to modeling - i guess i'll try experiemtnign somemore with the wind types etc never thought to look up the help to learn abit more about them which is a good idea

you can get a lot of control by sorting different particles into groups, (applying group names) and having different effect (wind gravity etc.) with variable settings effect these groups, you can even have them change groups when certain events happen, like when the sand hits the crest of a dune it gets hit by multiple air flows, but while it's running along the body, it's controlled by a different set of effecters.

I would suggest using a simple collision object for the body of the dunes, and having the resistance of the collision object effect different emitters or groups. Or try playing with whacky collision objects the camera never sees.

Also remember you can animate the effecters, to get collision working you need to define a particle size, use the HV start (i think that's the right name) so it can run the collision simulation, and be sure to save out any particle motion data your happy with.

theres a lot of decent control there, at first it may seem as if nothing is going in the direction you want it to look, but if you play and dig long enough, it usually pulls through.

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