So, both of my two Vue 5 gallery renders so far were done with Global Illumination, and I jsut started a render with Global Radiosity but it told me it would take 26 hours so I stopped it and switched down to Global Illumination.

The question I have is, in what kinds of images will I notice the difference enough for it to be worth it?

What am I really going to get out of this kind of lighting? The Team Women, Cars, and Guns

Message edited on: 03/22/2005 23:06

"Vue 5 Global Radiosity, when should I use it?" Only if you've got a rendering network, otherwise never..... (just don't take my reply serious, I often can't even see the difference between a normal render and a gi render)

I'm not a Vue user (yet!)so you can decide for yourself how valid my answer is! :o) Aeikema's answer contains a lot of truth! Radiosity and Global Illumination is SLOOOOOW in all apps (some more than others)if you can get the results you want with conventional lighting (and with practice you probably can most of the time)go with that, it'll render a hell of a lot faster! GI and radiosity are generally most useful on interiors where it's difficult to recreate natural lighting by other means. They create great results on exteriors too of course but exteriors are easier to light with your basic lights and shadow maps etc. One thing I'd love to see in Vue is a way to create image based lightdomes, they're a great way to fake GI and render a lot faster. I imagine a plugin could be written fairly easily, are there any plugin masters that would be worth contacting about this? Finally, what's the difference between Global Illumination and Global Radiosity in Vue? They sound like exactly the same thing! - Baz

Image based, like HDRI? Vue has that.

Global illumination only creates a uniform light around your scene. Radiosity not only creates uniform light, but also converts any surface in your scene into secondary light source. It takes a while to get the settings right but the difference is noticeable.

"Image based, like HDRI? Vue has that. " Vue has image based lighting but no method for creating an image based light dome, that is a dome of spotlights (or other lights) that take there colour and instensity info from an image. It looks very similar to HDRI lighting but renders much faster because it doesn't rely on radiosity. From what Agiel says though GI may be similar to using a lightdome in Vue. Thanks for the info Agiel! - Baz

Actually, Radiosity in Vue is not as fast as in Cinema, but it's not as slow as in other programs. It's not bad, not bad at all, and if you are careful in giving it proper settings, it can be more on the fast side than on the slow side. For instance, I rendered a large image featuring ecosystem replicas of a lot of flowers and grass, many trees, two lights, and soft shadows (!) in just one night of sleep (7-8 hours). And it turned out beautifully. And Radiosity was turned ON for ALL vegetation!

Not bad 7-8hrs for one image, but now imagine doing 50 or more images for a project (without a proper network).....

well, I usually don't use less than 7-8 hours to work on a picture and finish it - actually, it's often much more than this. And sometimes I too have to sleep :-) So, provided that I have two computers I'm ok with it, one renders while I use the other. I don't need a network :-) (but I would if I made animations!)

For creating a light dome, check out the Backroom, under the Lighting section and go pay a visit to Rodluc2001's site :)

He created a wonderful Python program to create lightdomes for Vue 4 Professional. I haven't tried it in Vue Infinite but I bet it should work.

To answer your comment, creating a light dome is a cheap way to simulate when GI does automatically. It is usually the way to go to simulate GI in software that do not support that kind of light natively (Poser up to 5, Bryce, etc).

Message edited on: 03/23/2005 11:43

Attached Link: http://www.renderosity.com/messages.ez?Form.ShowMessage=2063735

In the linked thread I made a visual comparison of the effects of GI, GR, and associated render times. In my experience GI works miracles for any form of architecture, but also for plants etc. It brings out heaps of detail in shadowed areas, and lots of nuance in the shadows themselves. It takes away the flat look that non-GI renders have. The effect is particularly noticeable in scenes with no direct sunlight. My recent gallery post "Mountain stronghold" looked absolutely hideous in non-GI preview renders, but turned almost photorealistic after GI was switched on. The added benefit of GR is less clear to me. In fact, in the attached link I think the GI image looks better than the GR. Both take a lot more time than non-GI, but IMHO the result is worth the wait.

Attached Link: http://www.renderosity.com/messages.ez?Form.ShowMessage=1955053

Also available from the Lighting section in the backroom, here is a comparison I made on different lighting types with a Poser character.

"For creating a light dome, check out the Backroom, under the Lighting section and go pay a visit to Rodluc2001's site :)" Cheers Agiel! "To answer your comment, creating a light dome is a cheap way to simulate when GI does automatically. It is usually the way to go to simulate GI in software that do not support that kind of light natively (Poser up to 5, Bryce, etc)." True to a point. I'm used to Cinema4d which has an excellent radiosity engine. If you want high quality, artefact free GI though it can be pretty slow. If you use lightdomes you can get similar results much more quickly. Better yet, use image based light domes (from HDRI or normal images) and you can get nearly identical results much more quickly. Of course not using radiosity means no colour bleed and the shadows probably lack a bit of detail but it's a boon for a tight deadline! :o) - Baz

Attached Link: http://www.deepdarkdigital.com

In many cases you can jack down the radiosity settings to say -.5 which will speed up the render by a factor of... well alot.

Say I get a reading of 3 hours at default radiosity settings, after jacking it down to .5 you might be able to render that same scene in 25 minutes, give or take.

It depends on how big you plan to render out... the smaller the final image (say less than 1024x768) keep the quality around -.25. At say 4400x3300 lower it down to -.5

Also, I have found that radiosity if really only useful in scenes NOT having to do much with trees or terrains or whatnot. For those types of scenes, stick with Global Illumin (also try jacking down the quality because it can do wonders for speed without sacrificing too much quality).

I have rendered out many radiosity scenes up around 3200x2400 and trust me I'm a stickler for quality of the final image,... but also hate waiting more than 1-2 hours for a final image.

Also one other note: In the render panel, make sure to set your own user settings, don't pick one of the presets. This allows you to lower the quality setting of the AA as the resolution of your increases (because too much AA of images around 4000x3000 pixels where the intent is to edit them, then rescale down for display at a lower resolution, is a total waste of time).

My typical settings: In render panel: 2 of 4x AA settings, limit at 80%. Overall quality set between 46% and 55%.

With these settings I notice almost zero difference when jacked up to higher levels but the time saved is incredible.

I don't find the need for network rendering at the moment. I have a fairly decent 3.2ghz HT enabled 1.5 gig machine and rarely get scenes that take more than 20 - 25 minutes at 2000 pixels horizontally.

One final comment: Vue's "estimate" time remaining indicator is VERY VERY inaccurate unless you do a complete pass in tiling mode (which is now not available at higher resolutions). This is due to the fact that different types of materials take widely different times to render and a given chunk of an image may fool Vue into thinknig the scene is going to take 50 minutes, when in fact, once it gets past that area, the rest of the scene may only take 5 minutes.

ANother Radiosity tidbit.... if using Poser, beware of multilayered transparency hair surfaces. (it's not all alpha mapped surfaces, just poser hair materials for some reason) That will bump your radiosty times up enormously. I did a couple of test scenes with and without a particular type of hair, and the time, for the exact same scene, same figure was like 2 minutes without, 30 minutes with.

Useful info dk3d!

Yes, thanks for the info Dk3d, this will definately help a lot when I finally get upgraded from Vue 4 Pro to Vue 5 Infinate at work and try to get some radiosity and GI into the renderings!

I use radiosity whenever I want VERY realistic lighting. In Vue 5 it works well together with the HDRI, giving a very natural look to the result. The downside of that is long render times. The first rule is to use only standard terrains unless you absolutely MUST use a procedural one. Those eat up render time faster than Carter makes little liver pills. The other thing is to tone down the quality to the lowest point that gives reasonable results. If you have a render farm and Vue Pro or Infinite, then by all means turn it up. My render farm is only gonna consist of two computers for quite a while though, and I only have Esprit anyway... But I've been tinkering with renderers since DKB and Vue's is certainly one of the best I've seen!

Actually, as a rule of thumb, the closer you need to be in scene, the higher you need to bump your radiosity quality factor. So, if you are working on portraits, you need to increase it around 1 or 2. If you want to use radiosity on large scale scenes, drop it below 0 (-1 works well according to czarnyrobert).