Smooth partikel rendering

Discussions about simulation, hair and cloth in SOFTIMAGE©
Pancho
Posts: 659
Joined: 19 Sep 2010, 11:28

Smooth partikel rendering

Post by Pancho » 11 Dec 2012, 18:44

For a particle animation I need to smooth out the effect I already got. Even if I go up to millions of particles, I'll see the single ones in the darker density areas. The luminous amount is controlled by the particle density. The effect itself looks nice, but I need to get rid of the "grain". Are there any tricks?

I tried to use a grid in the same plane as the particles which uses an ice tree with "get closest points". The amount of points in a certain area the controls a weight map value. Unfortuntely this takes way too much time to calculate as the grid needs to be very dense.

I wonder if there any other tricks to make this look better. After all this seems to be a quite common effect type.

Cheers
Pancho
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ActionArt
Posts: 853
Joined: 25 Nov 2010, 18:23
Location: Canada

Re: Smooth partikel rendering

Post by ActionArt » 12 Dec 2012, 00:11

To render point clouds you'll need something like this:

http://www.mootzoid.com/wb/pages/softim ... emrpc4.php

Also, Fury from Exocortex does that. http://exocortex.com/plugins/fury2

You can also play with using "blobs" as particles (see SI documentation) and using the volume shader. It may be tricky to get what you want.

Pancho
Posts: 659
Joined: 19 Sep 2010, 11:28

Re: Smooth partikel rendering

Post by Pancho » 12 Dec 2012, 09:09

Thanks for the tip, but I guess that's not really what I'm looking for (the plug ins). They would just enable me to render a higher amound of particles, but the problem of the graininess would still exist in certain areas. Meshing the whole thing would give me the same problems. Just a few particles in an area would cause wholes in the mesh.Probaly I need to use sprites with a diameter depending on the particle density. The higher the density, the smaller the radius.

Or I need to do it in post.

But thanks!!!

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ActionArt
Posts: 853
Joined: 25 Nov 2010, 18:23
Location: Canada

Re: Smooth partikel rendering

Post by ActionArt » 12 Dec 2012, 14:54

I'm not sure sprites would work to well if it was animated. The blobs I was referring too aren't meshes, just the way volumes of volume particles are blended, it might be worth a try.

Fury lets you blur and blend particles to get a perfectly smooth and noise free effect. It can look quite nice but it is a bit expensive so depends how much you need it.

I haven't used rpc but I think it can do the same.

Just some thoughts.

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druitre
Posts: 467
Joined: 25 Jun 2009, 23:35

Re: Smooth partikel rendering

Post by druitre » 25 Dec 2012, 17:41

Hey Pancho, I read this a while back and it stuck. Basically I'm curious too if it's possible to do this type of render out of the box, with MR. I came up with something: maybe it's already useful the way it is but I'm sure it can be improved upon.

It's a compound that sets size and transparency on particles depending on density, with some adjustable parameters. In combination with a (very simple) spritesetup in the rendertree and the right MR settings it flies through large numbers of particles easily - about a minute for a full HD frame w/1.000.000 particles (actually, amount of particles is less of influence than screen area covered).
pointcloud.jpg
render.jpg
with_compound.jpg
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druitre
Posts: 467
Joined: 25 Jun 2009, 23:35

Re: Smooth partikel rendering

Post by druitre » 25 Dec 2012, 17:52

Here's the compound + example scene. I've added a cached pointcloud plus an image to use as sprite. Probably makes quite a difference what image you use.

About the scene and MR: it's essential to use rasterizer and set all to lowest values, except for the max depth and refraction values. All other methods take ages to render.
Set Size and Alpha Relative to Density.rar
http://filetransfer.snackbardesiree.com ... mple03.rar

Please feel free to comment, improve, or whatnot. I added some comments in the compound to explain my muddled mathematical mucking about.
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