Just about everything is faked in cg, but in my experience with Vue, Carrara, Modo and Lightwave, I’ve come to expect that proper GI should stem from the lights in the scene. If you have an interior shot and you put lights in the lamps of the room with GI activated, you will have global illumination. In Poser, there is IBL. I can see that IBL can create a GI-like effect if you use a light dome photo that will generate multiple lights. However, if you light a room with one IBL light and expect it to bounce around and create realistic lighting like it would with genuine GI, you will be disappointed. 

Poser 8 doesn't seem to have lights capable of radiosity or genuine GI. 

That's because you're supposed to enabled IDL, not IBL.

IDL doesn't appear on the light options for "Create Light." and I couldn't find it in the Light parameters or properties panels. A term search of the Poser manual for IDL came up empty. Is IDL a light function? 

IDL probably means "Indirect Lighting." Indirect Lighting is mentioned once in the manual in the "What's New" listing. 

How do you activate IDL?

render settings.

Ok, thanks.
 

IDL = Indirect Diffuse Lighting

This turns on true GI.

yes, just to confirm, it actually works - even with no lites.

I'm liking IDL. It's the real deal. 

Congratulation, and condolences, now you can't live without it.

If you have read the manual before use  :-)

Anth - the manual is no help, IMO. My copy (a beta) has only a couple paragraphs on IDL out of over 500 pages. Is the finished manual better? I never downloaded it.

Not sure they ever updated the finished manual from the beta one - looks the same to me.

Ok i agree, but page 294 explain where activate global illumination, after is there many threads about this in the forum :-)

Is there a technical difference between IDL and GI, aside from "IDL" not leading to any data when you search the Poser pdf?

It's exactly the same thing ;-)

Not exactly the same.

Global Illumination (GI) is a generic term that describes any algorithm that takes into account secondary lighting, i.e. light that did not directly originate from a "light source".

Indirect Diffuse Lighting in Poser is a particular implementation of GI. There are others. A couple that come to mind that are GI but are not what Poser is doing with IDL are radiosity and metropolis light transport (MLT).

Saying Poser IDL is the same as GI is like saying "truck" and "vehicle" mean the same thing. A truck is a kind of vehicle, but not all vehicles are trucks. IDL is a kind of GI, but not all GI is IDL.

In fact, a key word in IDL is "diffuse". Poser only deals with diffuse secondary lighting. It does not deal with specular effects, which is shame. Most other apps that do some form of GI do it fully.

Quote - Congratulation, and condolences, now you can't live without it.

You said it lol.

Quote -

In fact, a key word in IDL is "diffuse". Poser only deals with diffuse secondary lighting. It does not deal with specular effects, which is shame. Most other apps that do some form of GI do it fully.

i never heard of specular bouncing.

specular is a cheat for reflections. and we can have more bounces for reflection. so if we could use soft reflections we could do specular bouncing

from what  i understand GI and IDL was always only diffuse.

Why shouldn't specular bounce ? Caustic light patterns on walls etc. are specular

Nobody said it shouldn't bounce. It simply doesn't. Poser IDL is fast because of the many cheats it applies. Among these, is to ignore specular effects.

Oh, wait - ice-boy is saying it shoudln't? That's not right. It should.

VRay, for example, implements GI caustics. Here is an excerpt from the VRay rendering parameters manual. Notice the problems it can cause - mentioned below.

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GI caustics represent light that has gone through one diffuse, and one or several specular reflections (or refractions). GI caustics can can be generated by skylight, or self-illuminated objects, for example. However, caustics caused by direct lights cannot be simulated in this way. You must use the separate Caustics section to control direct light caustics. Note that GI caustics are usually hard to sample and may introduce noise in the GI solution.

Refractive GI caustics - this allows indirect lighting to pass through transparent objects (glass etc). Note that this is not the same as Caustics, which represent direct light going through transparent objects. You need refractive GI caustics to get skylight through windows, for example.

Reflective GI caustics - this allows indirect light to be reflected from specular objects (mirrors etc). Note that this is not the same as Caustics, which represent direct light going through specular surfaces. This is off by default, becase reflective GI caustics usually contribute little to the final illumination, while often they produce undesired sublte noise.

VRay caustics are pretty slow to render - you need a lot of photons to get a clean result.  Well worth the effort though.

Luxrenders caustics look amazing but you need about a week to render the thing