Godrays 09

[Marc]

Hey all

So now that we have all the fancy volume stuff in 9.5 (and beyond), has anyone figured out an elegant way to handle Godrays? I've been playing around, but my meagre attempts all seem hacky for my tastes .

If not then I'll be sure to post something if I get it right. Seems like this is a perennial question that never really seems to get answered satisfactorily.

Thanks

Marc

[claude]

Usually, the god rays are done in comp, but for a 3d version, have you tried a large plain volume primitive with just a few divisions ?

You will need to adjust the 'volume step size' in the mantra sampling tab.

[Marc]

Yeah we would do it in the comp, but it's for an underwater scene (midday) and it's quite an active camera, so the 2d gag isn't working as well as we hoped.

I have a large volume with a noisy shader applied and it's working great for the underwater fog. Getting the rays in it is proving to be a trickier proposition though.

[symek]

Yeah we would do it in the comp, but it's for an underwater scene (midday) and it's quite an active camera, so the 2d gag isn't working as well as we hoped.

I have a large volume with a noisy shader applied and it's working great for the underwater fog. Getting the rays in it is proving to be a trickier proposition though.

Does it have to be volume based rays? Doesn't zmap-fog approach work for you? It usually woks in "underwater" cases (and under budgeted - unless lot's of composited layers with transparency screws it up).

[Marc]

Do you mean the litfog approach? It works, but I was hoping there would be a snazzier way with the new volume rendering and all. It also has its flaws, and it's not exactly what I would call quick .

M

[claude]

Mark Elendt talks about light fog and volume rendering at the end of the Rendering with mantra masterclass.

http://www.sidefx.com/index.php?option=com...&Itemid=132

[JoshJ]

I was just checking out this plugin in max for volume lights... haven't tried it though

http://www.afterworks.com/ScatterVL.asp?ID=1

and if you want to do it in 2d/3d, there's trapcode lux for AE, you control them with after effects' 3d lights:

http://www.trapcode.com/products_lux.html

both are probably better than a fake 2d rays effect if there are drastic camera moves, and might get the job done quickly if you're in a crunch.

still would like to see a good solid mantra solution for this too.

[rybow125]

I know this is a late post to this but I ran into an issue with creating godrays in a project I was doing. A file is attached on how it was done.

Basically, a 20 X 20 grid was created with a mountain SOP. In the Offset of the Mountain, an Expression was created to animate the surface. A group was created for the grid using the rand($PT) expression. After that, a delete SOP was used on the group to delete the random points and allowing the light for the rays to poke through. The light can be place anywhere above the grid itself.

This may be an old technique used but, I thought I would throw it out there for everyone

RaysOdforce.hip