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Tehuti
11-26-2005, 05:31 PM
How would I go about texturing each half sphere to have a volumetric noise around the whole surface? So far I have only been able to create a 2D texture on a Disc with Noise on an alpha gradient. (See image).

Ideally I need this to extend around the objects. I have tried glow and fog to no avail. I could do the noise in post if i can at least get a smooth grad. Possibly Pyrocluster on the spheres points - but I canít work out how to place particles on points.

This doesnít need to be animated at present (enlarging spheres from centre point) but a solution that could incorporate that would be most useful.

Any pointers? Thanks in advance.


Dean

http://www.deanbaker.pwp.blueyonder.co.uk/3d/molecules.jpg

mihkeltt
11-27-2005, 02:17 AM
i have not tried such soulution myself yet, so here's my guess. in 9.5 you can take use of the hemisphere area light or apply light to a model and make it visible with falloff and noise. just some guidelines. hope it helps

Artanis
11-27-2005, 06:47 AM
Visible light is disabled for area lights, unfortunately.

Since it doesn't need to be animated, use the TP Polygon Emitter object in the library with 0 speed to generate the particles on the spheres. There's a way to make them stick, but it's more involved.
Anyway, from there, apply Pyrocluster to the particle group.

If you have Storm Tracer you can use that, too. Just skip the particle stuff and apply it to the spheres.

[edit]
actually, if all the animation is just a scaling, then you can use the TP Object Collision to move them, but the moment you have rotation or position animation you'll need to make them stick.

christianS
11-27-2005, 09:52 AM
Hey

Since you want a spherical volumetric model, this actualy is easy. Just layer many (hemi)spheres like an onion, starting with a very small one to a very big one. The number of spheres determines the quality of the rendering. The spheres can be scaled very easy with the plugin align-assistant or maybe other plugins.
Set Ray depth of your render-settings to 500.
Generate a new material, use a gradient in the trasnparency channel, set tit to 3D-spherical, adjust the gradient to your needs, activate turbulence (or multiply the gradient with a noise). Copy this gardient to the color channel and invert it with a colorizer (you could also use a constant color here, but transparency works better on dark areas).
Trying it myself right now. This takes quite some time to render, but it looks good! I'll post a shot when it's ready

chris

Tehuti
11-27-2005, 01:01 PM
Hi all, thanks for your ideas. I did try the area light, until I found no visible settings :sad:

Thinkiní Particles eh? Time to get the manual out, have never opened that door. Before I go too far down that route - in view of using Pyrocluster to get the effect, can Pyrocluster create a strong contrasting gradated noise similar to my texture?

Ah, christianS, yes, I do remember jeremyw used to use that effect back in v7/8 using volumetric shaders to alpha out parts of the shape. Canít wait to see what you have produced. Render time isnít a problem.

Should have time this evening to get back on the job and get it a little further.

christianS
11-27-2005, 01:15 PM
Hi

Here is my result:

http://img366.imageshack.us/my.php?image=volmolecule2id.jpg

took about 10 minutes to render on my xp+ 1800 1GB RAM

I used 200 spheres. Adjusting the material takes some time though, because test-rendering take too long.
But i think it's the easiest approach for that task.

Tehuti
11-27-2005, 06:02 PM
Yes, thatís looking VERY close. I have managed to get to 90% of what you have, :banghead: though not sure whether itís my lighting and/or specular settings...

Originally I had my grad in the Alpha, rather than Transparency, and the colour coming from the Luminance rather than Colour channels. If you have time, have a look at the attached file, I have the material positioning exactly right, but itís just not rendering as well as yours.

Molecule.c4d (9.52) (http://www.deanbaker.pwp.blueyonder.co.uk/3d/Molecule.c4d.zip)

SeanL
11-27-2005, 07:02 PM
This rendered in 1 min, 10 sec. I used the TP polygon emitter for this...render time was 1 min, 10 sec so there is room to use smaller particle geometry and tweak to get a particle gradient if that's what you are looking for.

Tehuti
11-28-2005, 11:54 AM
Interesting Sean, I will have a look at that solution, though I need to make sure the density of the 'molecules' can be controlled enough to follow a sine wave, which is easier to control using a grad texture. Hopefully pyrocluster can produce some contrasted noise.

Dean

christianS
11-28-2005, 03:33 PM
Hey Thehuti

I had a look at your file and it is allmost identical to mine. I used other lighting (2 sources), but thats not very important. I guess you just have to fiddle with the parameters, as i did ;-)
I could send you my file if you give me an email adress.

CU Chris

BeccoUK
11-30-2005, 03:35 PM
http://digital-depictions.com/rf3_images1/particle.jpg

http://www.nextlimit.com/nextlimit/

Realfow3 from Next Limit is also an ideal tool for placing particles over a surface which can be volumetrically rendered using the free FlowTracer shader, also from Next Limit.

The simple example above uses a low res emitter and a volume daemon to destroy particles at the edge of the object. Very quick to set up too but refining the end result would add to the time taken.

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