Radiosity?

[Per-Anders]

well for just a sphere on a single plane you could probably get away with teh default settings, and that hsould render pretty swift. things to watch out for:

skly and floor objects, cause the min/max sampling to go to rather intense levels, so avoid using these fi possible and use either large spheres for the sky, and plane/poly objects instead of floor/ground objects.

stochastic mode will take longer than the standard mode. however it's results are more accurate, if when lower setings are used grainy.

the settings that will affect the rendertime the most as too high diffuse depth, this controls the number of bounces the rays have, which of course means that each extra bounce increases the render time. min/max samples, too high samples and you'll end up with long waits, too low ans your image will be blochy. accuracy, according to mv this has little bearing being merealy a control over teh pread between min/max samples, however too high and you may end up waiting forever as it forces the number of samples to all be at the max samples level.

size of the image is a fairly major factor too. while the prepass shouldn't be affected too much by the size of the render as it's taking samples from specific points the actual cleanup will take forever.

any use of transparency o reflective objects slows down radiosity.
use of transparent object that as diffuse/blurry, or reflective objects that use blurry reflections will make radiosity renders take literally forevver, but then these effects take a long time normally.

experiment with the simple sphere on a plane object and single light for a bit you should find you'll end up working out how to get good results. radiosity is very slow even with the best solutions and fastest computers.. so bear with it. good luck :)

[FusionDG]

In the infamous words of the USA's past der Schlickmeister, “I feel your pain”.

http://www.cgtalk.com/showthread.php?s=&threadid=39046

Here are some additional pointers that Strat, another C4D user, has given me that have been helpful that I have saved in a file:

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“With external scenes 1 bounce simulates GI perfectly imho, internal scenes will sometimes require 2 but i rarely go over 3.
if you got internals (or externals like night time shots) where lighting is poor and relies on bounced light (gi) then a value of 2, 3 or 4 may be required, but as i say, i tend to steer clear of this.

also, you know what colour bleeding is? this helps to simulated the GI effect too. i use a diffuse depth value of 1 most of the time but i also play heavily with the material's 'saturation' levels. this option should be use on the object RECIEVING gi and is a spinner to set the amount of light bleed received from other materials. if the lighting levels are rather low and need pepping up a bit try using the saturation option. i love it!

you may also want to use render tags to optimize rendering even further. ie, not every thing in the scene needs to generate/recieve radiosity does it? so why use it?

GI to metals - in theory, if you think about it, why use GI on anything reflective? ie, metals, mirrors etc... i usually switch 'GI Recieve' to off (found in material editor) for mirrors and windows, but keep full GI on all metals. but again, play around you may find a sweet spot.

render tags can force objects to render with radiosity or not, at whatever percentage you choose. the illumination controls in the mat. editor controls individual material gi settings.

And remember, things that dont need gi too much, like tree leaves, scattered grass etc.. turn the gi transmit button to OFF, else long un-needed render times will be there.

Stick to normal simple materials if you can. proceedurals and SLA take allot more processing than normal materials.

minimise the render window when rendering and dont continue editing or multi tasking durring rendering. all slows the process down.

dont use reflection blur in the material slots, it takes forever to render. instead render ur image out as a multi layered .PSD or photoshop file and blur the reflections out in ps l8r on. much faster this way.

dont bother trying caustics - in the main archi renders dont use caustics. not needed and not noticed."
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And coming here has sure helped me. All of the C4D users have been nothing but patient and helpful. I try to do as much homework as possible before I ask any Q's so not to waste their time, but it seems I always end up feeling stupid anyways, no fault of them, just my inexperience. Oh well, part of the fun of being a greenback I guess.

I guess if we love it, things will work out with persistence, patience and an eagerness to learn new things.

Best,

[awaiting that “magic” perfect GI button in C4D R9 :D]
Paul

[Kotayus]

well...ive been getting better results...quick questoion, what are good settings for a sky dome? how big should the radius be? 10000m? 20?

EDIT: still some artifacts under the sphere, what would be good settings for soft shadows? currently i have an omni at 5% with shadows set to soft, should i try a different approach?

http://www.xenodesigns.com/imagehost/gi1.jpg

and

http://www.xenodesigns.com/imagehost/gi2.jpg

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