particles and volumetric rendering and wispy snow?

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Hello! im kinda new to houdini, im an pretty experienced maya artist that are trying to specialise myself now more into effects at my work and i think learning houdini is the step to take to become a more professional effects maker… But as an aspiring vfx artist i have some questions i hope someone can answer

1. Im going to make wispy snow on a flat snow landscape. The type that travels over the snow surface and does some swirls (almost like loops) here and there. I have tried doing particles emitting randomly from a grid and collides with a groundplane for the main particle motion. but i have trouble getting the wispy effect on the particles, and the random “loops”. And since im new to all this houdini thinking i dont know how to render the particles really, if i should render some volumetric iso or sprites or maybe do this whole thing with the smoke fluid solver? or use a lowres fluid solver to drive particles?

2. Same project includes a cg polarbear walking in hard snow and im going to make the snow that sprays up from the feets when he walks. Same problem here with the rendering mostly, fluids or particles solution?

3. How to make particles move in a vortex movement in a popnet? sop particles works with metaball+force and i read somewhere about vortex in dops, but how to make vortex type of movement to my particles in pops? do i need to learn some more vector math to make it in vop?

Sorry if this all is simple things for you all, but i gotta start asking somewhere since we dont have an houdini artist at work and i find it hard finding good production quality tutorials for houdini for volumetric/particle work. I bought 3dbuzz technical effects wich was pretty good and professional tho
Magnus Pettersson
Lead Effects TD @ Storm studios
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1. I would recomend using a low rez fluid solver to drive the particles. When you advect particles you are free to also use other forces on top to add even more detail. Add a wind SOP with some turbulence, or you can put a VOP POP and do your own turbulence with Antialiased Noise which I found creates some nice effects. You can also try using curl noise.

2. A particle based solution will work best I think. Again, i'm a big fan of the wind/noise POP as this adds nice fluidlike behaviour without the complexity

3. I would recomend doing the appropriate vector map in VOPS. Or you can set up a tornado like fluid behaviour and advect particles.


I know what you mean about learning, I'm in the same boat. However if you really dig most of the information/sample HIP files are there. Unfortunately there are many ways to do things in houdini, not one solution is the “correct” answer. You will be surprised as to the amount of thigns you can do knowing only a few basic things.
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Ah thanks for the help! If im using a low rez fluid solver to drive the particles, whats the best way to get them rendered out then to get this volumetric snow thats flowing over the ground? i guess if i find a good way to render it i guess both question 1 and 2 can use same setup for the render part.

VOP POP and do your own turbulence with Antialiased Noise which I found creates some nice effects. You can also try using curl noise.

Ah thanks i never used them before in houdini since im pretty new to vops and all that, i had a play with them both and im not 100% sure how to use them, i got a result when i connected it to velocity for the particles but im not sure how to get full control over it yet, need to play more with it so i understands whats going on hehe.. i read in the help about the curl noise which looks pretty powerfull, once i know how to use it.
Magnus Pettersson
Lead Effects TD @ Storm studios
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