I have been doing alot of reading lately on advanced lighting techniques used in theCG Industry particularly Image based lighting and ambient occlusion. it may surprise some to learn that these features are used very heavily by ILM(industrial light&magic) in their CG effects /composite work for starwars and such Poser has this capability but I rarely see it used ( at least in most online poser galleries) anyone have any links to really well executed poser6 renders using IBL and AO thanks

Attached Link: http://www.renderosity.com/viewed.ez?galleryid=1068378

Well, I'm not sure I'd call mine "really well executed", but here is one I did the other day. (Warning Nudity) I wasn't intending to do a good "art" pic, per se, but rather playing with IBL and AO with an attempt at indoor realism using only a minimal lighting setup. If you want to know more, I can post the light settings and the probe I made myself.

Attached Link: http://www.renderosity.com/gallery.ez?ByArtist=Y&Artist=Mec4D

Have a look at Cath's gallery, she did some nice examples of integrating Poser renders in photographs using IBL/AO.

Here is a little study of my pic with three different light setups. The first column is with an infinite light and a spot light. In the second, the infinite is replaced with an IBL. In the third we add AO.

Hope this helps show what you can expect from IBL and AO.

Attached Link: http://www.renderosity.com/viewed.ez?galleryid=1068586&Start=1&Artist=dlfurman&ByArtist=Yes

Here's one recently posted.

Holy guacamole. Cath's stuff is amazing. Did she really do that in Poser? And are those skin textures for sale yet?

Here's one I did after getting the Girl from the PC Bonus selection at DAZ. It uses the Lagoon light in the Poser 6 IBL Ambient Occlusion lights, with another light in the smae place set to specular only. Not brilliant, but shows the shadowing you can get from AO.

Thanks guys yes Cath's work is amazing!!

"If you want to know more, I can post the light settings and the probe I made myself." Yeah, I want to know more. :O)

Attached Link: http://www.physicalc-software.com/tutorials/ibl/

I use a slightly modified version of the traditional IBL technique which IMO gives much better specular effects and shadows - which uses a modified version of stewers poor-man's IBL script (so above link for the technique). I also find that the material based AO is a) faster, and b) gives much more control than light base AO.

Message edited on: 10/19/2005 16:20

This is the light probe image I used.

The image was actually made for another scene. So it is not "accurate" because it doesn't reflect the actual surroundings of this scene. But it doesn't really matter that much. It produces a believable indoor lighting. I'm now experimenting with making more custom light probes. (The red corners are the result of a red object behind the mirror ball in the scene I used to make the probe. Poser doesn't look in the corners so it doesn't matter.)

Anyway, set up an IBL light with this image plugged into the Light Color. Set the Light Color to WHITE. I used intensity 37% - any values around 35% to 55% work well. Set IBL COntrast to 1. On this light, enable Ambient Occlusion. I used a strength of .25 and left the Scene AO Options at the default values.

Set up a second light to bring out highlights. It can be infinite or spot. In this image it was a spot light with depth map shadows. Do not turn on AO for this light. Intensity was 44%. Angle start/end was 0/130. Distance Start/End was 0/0. XYZ Rotate was -45/38/-12. XYZ Translation was 10/14/10.

Play around with the values. Do fast renders with no raytracing to get the desired light levels right. Then turn on raytracing to enable the AO function. Unless you want reflections in the scene, you can set the raytrace bounces to 0 for faster rendering.

I know there are better setups, as face_off has shown. But since you asked, I tell :)

Now I'll "pose" another teaser - do you want a mini-tutorial on how to use a mirror ball to render your own custom light probes in poser?

the link to the light gen plugin isn't working :(

Hey baggins - what a cool idea. Build the room scene - then put a 100% reflective sphere in the middle, and render with the camera pointed on the sphere. Gives an IBL image generated from the actual scene!

pbm - email me.

bagginsbill, I would be very interested in your mini-tutorial! :D

bookmark

Yes Paul thats it. I bet you've already made a few now, eh? Above is the IBL probe for my living room scene. So now help me figure a solution to a problem with this technique. The middle of the ball shows what is behind the camera. But to get good angle coverage, I need to move the camera REALLY far from the ball and then use large focal length to fill the image with the ball. So now the "front wall" of the scene is in front of the camera and it blocks my view of the ball completely. This only happens in render. For preview, I can see THROUGH the wall. Why is a one-side square invisible from the back in preview but visible in render? Even if I check "remove back-facing polygons" it still shows the back of the wall. I haven't published the tut yet because of this problem. So far I've just moved the front wall far away and scaled it to gigantic size so it still mostly fills the ball. Any stray areas that stay black I just smudge in with photoshop as a post-process step. But this is not a good workflow step and I want to eliminate it. Plus, there could be more geometry to that area of the scene that just a one-sided square so ... Any thoughts?

The only problem with that technique is the IBL probe will lack the high Dynamic range that a real light probe has. Read at www.debvec.org for the brainy explaination. But still a cool idea.

Attached Link: http://www.renderosity.com/viewed.ez?galleryid=945840&Start=1&Artist=ghelmer&ByArtist=Yes

I'm kinda fond of this pic I did a while back... Only thing I didn't like about was V2's neck looks a little wonky!

Baggins - what about making the reflection sphere very small (scale to 10%) - then you can get the camera closer to the sphere. Was thinking about this some more - the IBL Image should create very bright areas for light sources. However rendering a light in Poser doesn't actually render brightness (ie. it doesn't actually render the light - just the result of the light hitting something). To get around this, you really need to add a props at your lightsources, and have them set to 100% white ambient in the mat room. ....or is the IBL image just a fill light - and you are keeping the main lights in your scene for illumination and shadowing?

Attached Link: http://www.renderosity.com/viewed.ez?galleryid=939313

I use IBL/AO a lot in my renders. Here's one of my earliest uses of it to match scene lighting with a photo background.

ghelmer - great render. One question - there is a light in the ceiling to the right - shouldn't that be illuminating her left side?

Attached Link: http://www.renderosity.com/viewed.ez?galleryid=1069454&Start=1&Artist=PapaBlueMarlin&ByArtist=Yes

I've really just started using IBL. I use face_off's OcclusionMaster rather than trying to get a universal setting from the lights.

Volfin,

You mean www.debevec.org, not "debvec", right?

Your comment about HDR is interesting. I could be wrong, but I don't think it matters in the least that these are not HDR probes.

In fact I'll go this far. I'm going to get heretical here and claim that, with respect to the use of light probes in Poser 6, HDR won't make any improvement whatsoever.

Here are my reasons.

First, Poser can only use a light probe for its calculation of diffuse illumination. That means this is not involved in refraction through dark glass or other tricky situations. It doesn't even use it for specular reflections, which is just plain silly, since it could pretty much use the same algorithm it uses for diffuse, i.e. perform a convolution on the probe and use the surface normal to select a value from the convolution.

Second, diffuse illumination INHERENTLY DISCARDS the detail and range found in an HDR image. Basically, for it to work correctly, it must calculate a "cosine-weighted integral of the corresponding hemisphere of incident illumination." For the math challenged in the room, that means "it must blur the heck out of the probe image first." This destroys a lot of detail, meaning that a low-resolution, LDR probe and a high-res HDR probe end up looking pretty much the same in 99% of situations.

Third, we have no control of the diffuse convolution function used. Which means that the same diffusion angle profile is used for all materials, which is just plain silly. Poser is doing rather inappropriate math on the lighting, so it makes little difference that the input to the lighting algorithm is lacking some detail.

So - we have crappy algorithms, little control on a per-material basis, and only use the probe for diffuse illumination, forcing the addition of other lights to create specular reflections and strong shadows.

Then, on top of all that, the AO algorithms in poser SUCK. It doesn't do the right thing at all. You can see it in how the AO shadows are so grainy and quite often come out the wrong strength at different scales. For example, its very common to get strong AO shadows around the bridge of the nose but give no shadow on the floor under the figure.

I'm just trying to figure out what we CAN do with it, because making truly photo-realistic images isn't going to happen with Poser 6. :-)

Face_off - Yeah I have no intention of modeling the light sources in the IBL probe. I think the IBL is just good for fill. Poser won't use the probe for reflections so there's no point in putting that in there. You have to put other lights in. What IS important, is if there is a light shining on a wall. That matters. For example, in my probe of post #11, you can see a bright spot on the right. That is coming from a light WHICH IS ON THE LEFT. So using this probe, increasing the light on the left increases the diffuse back-fill from the wall on the right! Pretty cool eh? When I use that probe in the scene where it belongs (pinup in a museum), I include the actual spot light on the left. If I change the strength or position of that spot, I have to recalculate the IBL probe. But it really works well. When I finally solve my problems with props in that scene, I'll post it. I wish Poser had a checkbox for "Auto IBL Probe". Then it could just do a quick lo-res render and take care of this all by itself. Its no more difficult than the pre-renders it does to calculate shadow masks.

Baggin's - if you are using this as a fill light - no probs on the other light sources. However, you'll need to get shadows setup on your standard lights - since the AO from the IBL will be very weak (as show in your render above) due to it's low intensity relative to the other lights. If rendertime is no option, can I recommend depth mapped shadows, 0.01 bias, blur 10-20 (depending on the light you are trying to simulate), map size 3072 (very important). If rendertime IS important, you'll need to live with smaller shadow map sizes (1024). Mmmmm, we've strayed a little off topic here....

Attached Link: http://www.renderosity.com/viewed.ez?galleryid=937237

This. Isnt perfect but has IBL and AO. Also the Lagoon light, I remember

Casette - that's really good!

I've recently started using IBL AO in my pictures and I'm totally in love with the effect!

Here's an example: Lost Boy

And another one here:

WARNING NUDITY

Regrets?- - - - - -

Message edited on: 10/20/2005 07:43

I think I'm really starting to figure out this IBL+AO stuff.

Here is a test render I did for the tutorial I'm working on. It finished in about 3 minutes. What do ya'll think about this one?

there still seems to be a lack of a "contact shadow" where her body touches the floor

Yep. I was trying to work on the skin tone from the IBL without confusing myself with what the AO was doing. So I had the depth map shadow for the spotlight turned off and the AO on the IBL turned WAY down.

Here is the render with the spotlight shadows turned on and the AO at 20%. I'm using 20 samples on the AO. The AO shadow is dirty. I'm not able to figure out any good settings at all.

In this render I turned the AO on to 100% so we can clearly see what it is doing. Of course you wouldn't want it on this strong.

I think the AO is crap. Look at all the splotches. And why is there so much shadow on her shoulders. In terms of percentage of occlusion of the hemisphere that lights those areas, it seems totally wrong.

Face_off, I know you said to put AO on individual materials. Can you point to some examples?

BTW: Face_off, I did what you said about the mirror ball. I made it teeny tiny and set the camera focal length to around 15000 mm. Works great! I didn't think poser would do the math for such a tiny object and such extreme focal length correctly but it did. So this lets the camera stay close to the mirror ball.

I think he means creating an occlusion node for every scene material not just trying to add general occusion for the whole scene he has a nice python script that does it for you so you dont spend hours creating nodes for dense multi-textured scenes. A/O is nice and all but there really is no substitution for real GI for stills IMHO :-)

Bookmark

Ok creating a node for each material is not going to do anything for this image.

The thigh material area is showing two kinds of problems simultaneously. To fix one, you must raise bias. To fix the other, you must lower bias. Can't do both at the same time on the thighs, right?

Attached Link: Occlusion master

Im not sure whats going on in your scene there as i dont use any of poser6's render options because i render in Carrarpro4 (animation) and Cinem4DR9 studio( hi res stills) both apps have real GI as well as IBL &HDRI support But the promo images on his store page look pretty good and properly shadowed.

I totally get how OM works and why I'd want to use it. But my problem here is I can't find any set of values that works for the thigh. Just the thigh. If I had OM, I'd still have to type in the three values for the thigh and none of them work. Aaarrrgh! Also, I'm a professional python programmer. I can make these scripts myself. But if there is no value for AO options that works for this thigh, then it doesn't matter whether I'm setting them manually or through a script. :)

Finally found a setting that works ok. It's still showing a bit of dirty chest, but its acceptable I guess.

The settings for AO are:
Strength: .2
Max Distance: .7
Bias: .01
Num Samples: 5

Here's the light probe I made for this scene.

I started with IBL all white. Rendered the ball. Saved the render and attached it to the IBL.

Rendered again (feedback) and saved.
Rendered again (feedback) and saved.
Rendered again and saved final you see here.

This is poor man's radiosity!

I used specular on the ball to pick up the spot light and spread that light around the room while keeping the highlight strong.

Gee, a few messages to catch up on! Baggins, your issue in post #36 is exactly the reason I think that material based AO is better than light based AO. However, material AO only has an effective distance of around 20 inches - so it's not so good for getting general shadows in the room. And it also does interesting things to the corners of walls. But it is awesome for foot-to-floor interfaces, and skin-to-clothing, etc. I suspect that light based AO was added to provide a shadowing system for IBL images, rather than provide a /better/ shadowing system than r/trace or depth mapped. So IMO, you are better off just using the IBL as a filler, and getting all your shadows from normal lights (ray-traced or depth mapped). Use normal lights for the majority of the light sources in the scene. Which is the whole basis of the tutorial I posted. Derive your lights from the IBL image (using HDRShop), use those lights for shadowing, and use the original IBL image as a filler. Using the tutorial, it takes 5 mins to set everything up. The biggest time killer is calculating the depth mapped shadows. The higher the quality, the longer the rendertime. OK, back to your system. The post in msg #39. Is the IBL image actually adding anything in this scene? Maybe a comparison render with just the lights so we can see the difference? Also, IMO the shadows are still a little way off. Check her right-hand-on-knee, and left-hand-on-hip - the shadows on both seem odd. The above render shows the shadows you can get with material based AO plus depth mapped shadows. There was no IBL filler in this scene - so it's got an "interior" feel to it. You can see I haven't placed her left foot correctly - however, the interface between her and the floor is pretty good - and all the lighting and shadowing was very easy to setup.

Attached Link: http://www.physicalc-software.com/forum/viewtopic.php?p=15#15

OK, did a little more testing on this. Light-based AO is very slow compared with your other options. See the above link for details.

bagginsbill, All of your points are 100% valid (including the URL) ;) I just figured I would throw that out there just in case someone mistakenly thought they could create actual HDR lighting for other applications this way. Even in Poser it still creates a more realistic lighting environment. :)

Well Face_off, I agree with AO being poorly implemented.

Neverthless, I think Poser's IBL is pretty good. As you can see in this montage, the IBL is contributing most of the total illumination and IMHO is very believable as in the lower right. If I swap the overall ratio to raise the spot and lower the IBL, it just doesn't look as believable. I've collected dozens of indoor photos and the light falloff is much more realistic with IBL. I can't post any of them because that would be a copyright problem.

My problem now is only that to finish the believability we need AO to go with the IBL.

Failing that, I'd like to try the HDRShop conversion of the IBL to a set of infinites as you suggest. But I too ran into the bad link for the plugin.

Sigh.
Even if I get HDRshop working, won't I still need AO to darken the tight spots? I'd still have the same problem with the crappy AO, right? Even in your nice pictures where you demo Occlusion Master, I can see some of the AO dirt. I tried somethings else. I made a shadow-only render to get the AO information and then I softened it in photoshop then multiplied the result back to the original unshadowed image. It improves the results a lot, but I'm trying to find a way around that onerous workflow.

Now that the weekend is upon us, I think I'll just give this a rest and start partying. No more Poser till Monday.

Thanks for all your help!!!!!

Message edited on: 10/21/2005 10:08

As you can see in this montage, the IBL is contributing most of the total illumination IMO, it is better to get > 50% of the illumination from non-IBL sources, and use IBL for the filler. That way you can use the nice depth-mapped and ray-traced shadows. Even if I get HDRshop working, won't I still need AO to darken the tight spots? Not sure what you mean by this. Either use material based AO, or thighen the bias us on the depth mapped shadows (to 0.01). Did you read the link in my previous msg - gives you the values. Even in your nice pictures where you demo Occlusion Master, I can see some of the AO dirt. I doubt it's AO dirt (since there is no light-based AO) - it's probably from the texturemap - that's GI Jill :-)

Bagginsbill and Face_Off, the work that you are both doing on material and lighting settings is of enormous value to all of us! This is a very complex subject that is not easy to explain in laymen's terms. Post 41 is reminiscent of Demi Moore ... intended?

Demi Moore? It is very loosely themed on Demi, but nothing like a genuine attempt to do an accurate likeness.

I got HDRShop to work, the lights just aren't what I imagined for the background. I kind of expecting something much lighter. There's also a wbile line around the figure which is probably from realism shine being too high...

Nice one Jeremy! Does this mean you finally got HDRShop to recognise lightgen? When it's too dark (as above) - up the IBL fill level - see step 6 of the tutorial on how to do this. That will also reduce the impact of the shine. You are right though - in this case it looks a little too shiny - the easiest way to reduce this is to reduce the Oiliness and/or Power sliders in the Realism Kit (Oiliness around 0.3-0.35 would be a good start).

Yeah, it finally recognized the plugin. I'll play with the fill level to see how it looks.

here's my second attempt