I bet I'm not the only one wondering what this indirect lighting is and does.

So I decided o do a small "with- and without"  comparison, attached below as a gif that changes bwtween the two. The only thing I changed was I unchedked the "indirect Lighting" on one render. Everything else is the same. Rendered with one light and the G2 Olivia.

The brightest one is the one with Indirect lighting.

Thank you very much!

Did you render with HSV Exponential turned on? Without it, we're seeing everything too dark, particularly in shadowed areas lit only by IDL. HSVE is like gamma correction, but easier to deal with as it doesn't modify incoming textures.

Set it to 2.0 or 2.2. Render again.

Also, put her over a white square instead of the black square, and render again. You'll be surprised.

Attached Link: BlinkyGIF of indirect lighting

Also, P8 without indirect does a better job than P7 on the oblique light between
the houses.

Note that the blinky-GIF is too large to store in Rendo so I put it on my website,
at the link above.

Attached Link: Snowy scene

Living in the Arctic as I do, and therefore a self-professed expert on winter, yeah, that looks like what happens when I go outside on a sunny day after a fresh snowfall.

Where's this HSV switch thingie that you're speaking of?

lostinspaceman

in the render settings. tone mapping

I actually did use the HSVE, but at the default setting of 1.60 since I wasn't sure what it did ^_^

Since then, I noticed your render settings and that you'd cranked up the IL Quailty a lot, so I tried that and this is the new result, also with the HSVE at 2.2 as suggested.

I also moved the floor so she's now at least partially overe a white tile (hard to know where the tiles go when they're procedural) - the main reason I put her on a black tile the first time was to better see the reflections in the shiny tile. But of course a black tile won't bounce as much light as a white one. I should have known :)

Nice, eh?

a good render Trekkie

1. V4 with one point light +AO no Indirect light. No Tone Mapping.

Mazak

Mazak

Mazak

One tipp: for your renders turn down raytrace bounce to 1-2. Higher settings are a time killer with Indirect Light (and transmapped hair). :blink:

Mazak

Raytrace bounces also appears to be controlling the number of GI bounces.  This means that, with a setting of 1, a given ray will touch one polygonal surface (like the character's skin) and then go on to be reflected to one other surface, and then stop.  in other rendering apps, a very small number of GI bounces typically results in uneven application of GI light, leaving you with a blotchy image.

In Poser the Raytrace bounces are:

0 For Shadows
1 - 2 For Reflections
3 For Refraction Transparency
4 For Reflections through transparency

You didn't see difference on GI with higher Raytrace bounce.

Mazak

Nevertheless, that's what the text of a saved scene file says it's doing.

The meaning of num bounces changed over time during beta. I'm not sure what it is exactly, but I know it does affect it.

I think the GI bounces is one more than the set value, and/or a reflection ray does not count against the tally for GI.

What I mean by that is this. Suppose you have a scene with GI. You add a mirror and observe the scene via the mirror reflection. I believe the scene will look the same, even though technically one more bounce is needed to get past the mirror. That bounce does not reduce the number of GI bounces used to calculated what is reflected by the mirror. Were this not the case, then things would look different when observed directly versus indirectly via a mirror.

I really think reflection depth and GI bounces should have been on separate controls.

Me too.

You people testing out GI... you're not going to get "real" radiosity lighting effects with a single figure on a ground plane. You're going to need props for the light to bounce off of, or an enclosed environment for the same reason.
The shadows for the figures above are all completely wrong in terms of realistic radiosity lighting, because the light is only bouncing off the floor and off the figure and then going... nowhere, off into the Poser universe never to be seen again.

Stand someone up in an empty room in real life. There's no way you'll get shadows like those without a very bright light, in which case you'll lose features on the person herself.

Quote - You're going to need props for the light to bounce off of, or an enclosed environment for the same reason.

I'm aware of that and I expect Bagginsbill is too, but it's good that you point it out.  Although, with GI bounces at 1-2 - if that's really what's going on with "Raytrace bounces" render setting, and it does seem to be the case - it's pretty much bouncing off the floor and off the figure, and stopping.

Mazak

Mazak

Quote -
I'm aware of that and I expect Bagginsbill is too, but it's good that you point it out.  Although, with GI bounces at 1-2 - if that's really what's going on with "Raytrace bounces" render setting, and it does seem to be the case - it's pretty much bouncing off the floor and off the figure, and stopping.

Well I haven't bought Poser 8 yet to test it out for myself. But I think it stands to reason that with only 1 or 2 bounces that's what would happen. Although in an enclosed room I'd think that rays would bounce off the walls and ceiling and back into the room, even with 1 or 2.

Quote - And here here with Raytrace Bounces 6 it looks more distorted !!

Mazak

And those are the artifacts that have me so very concerned.  They're worse if you have an enclosed environment instead of a simple ground plane.

That is what I mean Raytrace Bounce 1 look better than Raytrace Bounce 6. :blink:

Mazak

Well, while the artifacts are certainly bad, the lighting is closer to accurate on your second image.  Try loading a cube primitive and scaling that up so that it encloses your scene and the light and camera, like a room's walls would, and you'll see a VERY big difference.

You can get rid of the splotches only with higher Indirect Light Quality, Higher Pixel Samples and a Min shading rate of 0. But high raytrace bounce produce more artifacts.

Mazak

Or don't, that's okay too.

Attached Link: Interior scene

In this case I like the non-indirect better.  The indirect just seems overexposed.
No artifacts visible.  (There's a black speck on EJ's blouse, but it's there in both
versions.)

I suppose this is going out on a limb here...
But does Poser 8 have radiosity disk caching?

Hi folks. Guess what everybody is doing wrong?

What is your Diffuse_Value on these props? Is it 1? Hmmm? A white color with DV = 1 means what?

Anybody ... anybody?

It means that 100% of the light that hits the surface is reflected in each IDL calculation.

This is impossible in real life, and will cause over lighting and artifacts.

In real life, each time light bounces from an object, less is sent than arrived. With shaders that tell Poser to model an EQUAL amount of light is sent as arrived, that means each bounce is just as bright as the last. After six of these bounces, you have an impossibly over-lit scene.

I, of course, have been using shaders with DV = .8 for a long time, even before GI. My shaders don't blow up with Poser 8. All the shader you have gotten elsewhere likely do blow up.

A diffuse value of 80% or thereabouts is generally recognized as "more correct" in all the 3D apps, I suppose. That's one of the first things I ever learned about rendering.

While I don't expect that this is the cause of the artifacts I'm getting, I'll try that too.  It hadn't occurred to me to reduce Diffuse_Value.

Quote - I suppose this is going out on a limb here...
But does Poser 8 have radiosity disk caching?

I think it does, but not in a way you can control.  One of my renders left a file on disk with a file extension that seemed to relate to irradiance caching but now it's gone (written and removed automatically and silently).  I don't know if this is useful to you.

I agree, it's probably not the cause of the artifacts you see.

However, it will cause corners where two flat planes meet to blow up. Any slight numerical variations in angles in the last bounce could result in a localized difference of near 1.0 between two close points in the GI calculation.

When done with DV = .8, the contribution of the last bounce is only 26% versus 100% when 6 bounces are used. Ideally, you'd use more bounces than that, getting down to 1-2% variation in the last bounce.

I will try this with diffuse 80% too. When some renders finished I come back.

Mazak

Ockham, is it possible that you have lights in your scene that don't cast shadows? In reality, all lights cast shadows - running an indirect light calculation over an unrealistic input scene will inevitably result in an unrealistic output image.

Quote -
I think it does, but not in a way you can control.  One of my renders left a file on disk with a file extension that seemed to relate to irradiance caching but now it's gone (written and removed automatically and silently).  I don't know if this is useful to you.

It might be something Poser is using at the time of render but not later.
True disk caching, such as in Mental Ray and Lightwave, creates a GI light map or a GI samples map and stores it to disk if you have it set to do so. So if you re-render the scene, the GI is already baked into it and it doesn't have to recalculate it. That's useful if nothing in your scene is moving, such as a walkthrough in arch-viz, where only the camera moves.
If Poser 8 were doing that you would know it, as the render time would only be long for the first render and all subsequent renders would be significantly quicker.

Quote - I suppose this is going out on a limb here...
But does Poser 8 have radiosity disk caching?

Just to confirm, on a render I have going right now, after the "Indirect Lighting precalc" phase completed, Poser wrote a file named *.icache, leading me to think this is the light map.  I think when the render completes it will erase it.  I don't see any option to control this behavior.

Quote -

Just to confirm, on a render I have going right now, after the "Indirect Lighting precalc" phase completed, Poser wrote a file named *.icache, leading me to think this is the light map.  I think when the render completes it will erase it.  I don't see any option to control this behavior.

Ah well, thanks. :-)
Seems it's not doing what I was hoping. One day, perhaps.

Mazak

Mazak

Why such sharp shadows?
That is so totally not right for a GI render. Shadows should be sharp only where the object touches the floor and rapidly soften and fade towards the ends.

probably raytraced shadows with no blur, although I'm a bit surprised that what appears to be a shadow bias offset gap appears with higher number of bounces

I know Poser 8 doesn't have area lights, but what kinds of shadows does a luminous polygon create in a scene when used with GI?

Quote - Here a example with diffuse 0.8 on all objects and raytrace bounce 6.
Less splotches now! :thumbupboth:

Mazak

shading rate 0 ????
pixel samples 12????
raytrace bounce 6? 

holly s..... those settings are insane.

Attached Link: Snowy scene at 80% diffuse