Hello all,

I was trying to render some metaballs as volumes this morning. To my surprise, they all came out as a bunch of overlapping spheres. I was hoping the blobby field defined by the metaballs would render. I have attached an image with the metaballs rendered as geometry at the top and as volumes at the bottom.

Is there any way to get the volume render to match the geometry one better?

Thanks,
Koen

koen
Hello all,

I was trying to render some metaballs as volumes this morning. To my surprise, they all came out as a bunch of overlapping spheres. I was hoping the blobby field defined by the metaballs would render. I have attached an image with the metaballs rendered as geometry at the top and as volumes at the bottom.

Is there any way to get the volume render to match the geometry one better?

Thanks,
Koen

The metaball surface is created where the sum of the weights is 1.

However, a volume will render, even if the density is 0.1.

If you wanted, you might try changing the surface shader to subtract 1 from the density… I'm not sure whether that will do the trick though.

Thanks for the reply Mark, guess I am going to need to stamp it in a
volume after all.

This is for things like missile trails etc. I think it would be very handy if there was an option to render metaballs that looked as if I had converted them to a poly object, ran an iso offset and render that, but then without actually creatin the geometry or the volume.

Do you think something like that is possible?

Thanks,

Koen

Interesting thread… It got me thinking and I prototyped something but now I wonder how exactly how do we pass color info into a volume to mantra?
I assume this is a very basic question, but I've generated a vector volume from Cd I sampled from a point cloud. Now how do I make that data's way into mantra?

cheers

That works just like with surface shaders, just add a “Cd” parameter, that gets the color. I always use Cd.x Cd.y and Cd.z not sure if will work.

Also I found that if the colors are not exactly the same resolution, it wont work.

Cheers,
koen

Cool, thanks man!
I meant Cd…

Cheers

my friend Martin Matzeder wrote an article about rendering Metaballs as volumes a while ago, that might be interesting if you not already read it:

http://www.booyabase.de/?p=570#more-570 [booyabase.de]

best,

Manuel

Probably not exactly what your looking for, but you can always just apply a uniform volume shader and render them that way..

Make a subnet shop, in it connect to suboutput1 a properties shop and to suboutput2 a volume cloud shop. in the properties add the rendering parms, uniform_volume toggle, and volume density float. Just apply that to your metaballs, or any other geometry, and it will render as a volume, (quite quickly too)


zak