I am asking this question because i don't understand the benefits of face off's OcclusionMaster. Yes i know it adds AO to renders but what's the difference to using his Python script than adding AO to a selected light? or adding to the material in the material room? I would have prefered to see an image using AO on a light and one using OcclusionMaster to see what the difference is, has anyone done this???

It's not about anything being better. As far as I know, just like the Real_Skin products, this doesn't do anything you aren't capable of doing yourself. As a matter of fact, he hosts tutorials on making your own AO and Real_Skin without his scripts. Now if you look at those tutorials, you will begin to understand why exactly someone may want to purchase the scripts. It is a lot of work to make it come out right. (I should know, I had followed his Real_Skin tut for a coulpe of days, and I have been tweaking out my render for a couple of weeks now. I have yet to buy his scripts, but I may just get them after I prove to myself I can do it on my own.) The point is, it saves you time making really complicated Mat Room effects. It is by no means required for you to get the effects, it just makes you life infinitely easier. Hope that helps.

"Yes i know it adds AO to renders but what's the difference to using his Python script than adding AO to a selected light?"

Simple. Turning on AO for a light distributes the occlusion across the entire scene, so that every object gets it. Since AO is raytraced, this could mean much longer render times. Now as you may know, not everything in your scene will actually benefit from AO, so in some cases, turning it "on" in the light properties could be overkill. Not to mention, it's a lot harder to get the AO exactly how you want it on every object in the scene (for example, you may want it to appear darker on the ground than on the skin).

So the solution is to include the AO material node on just those objects in the scene that you want to receive it. Doing this also allows you to tweak the AO bias, strength, etc. seperately for different objects of varying size. It provides MUCH greater control an precision than distributing it from a light.

That said, OcclusionMaster makes the process of adding AO nodes to your materials much easier. Sure, you can add it by hand using the Python wacro that comes with P6, but the problem is, on objects with lots of material zones, you'd have to run that wacro on each of them, and tweak the settings by hand. Face_Off's script allows you to select what material zones on your object you want to put the node on, and you can change the bias, strength, and distance values for that node right in one convenient interface panel. Bottom line, it's just a lot faster and more convenient to impliment AO nodes in this manner.

Hope that clears it up a bit for you. ;-) Message edited on: 08/30/2005 19:49

Thankyou all, I now understand the idea behind it. For me it would save time altering the AO on the materials. but first i think i will get that ShaderSpider from Daz....hmmm

I'm thinking I might need to add occlusion master as well to my P6 toolkit. P6 is just looking more and more robust every day, dispite EF's silence on any additional service releases. I just hope they are listening to feedback from these Python gurus, because there's more they could do, if poser python implimentation didn't tie their hands...

Thanks for asking this question and thanks for the answers. I was wondering exactly the same thing! Hey, you know, I'm digging some of the new render options with P6, like the image based lighting and AO!

I generally just bite the extra render time on having AO on the full scene... HOWEVER, I have had a couple of scenes where I got weird shadowing effects on certain props due to AO, and in those cases, the only real workaround was to apply AO to the things that could handle it while avoiding those that could not. Occlusion Master was very helpful in those cases.

I usually only have one light with ao turned on and bias kicked up some, and then add spotlights or point lights without ao at all, and get good results, without high rendertimes.

I almost always use node-based AO, simply because reflection/refraction/transparency, mixed with AO, can slow the renderer down dramatically. Usually, I'll avoid putting occlusion on these kinds of materials if possible. If I don't have a lot of transparency or raytraced materials, then I'll just go ahead and use it on a light, but that's rare.

Another problem I've experienced often when dealing with AO on a light is that you have no control over the strength of the AO throughout the scene. What I mean by that is, often times you'll get too much occlusion in some areas, and too little in others. It's very difficult (or impossible) to get the strength, bias, and distance perfect for every object in a scene. Node-based AO helps solve this.

It's good that we have both options though.

Message edited on: 08/30/2005 23:54

Yup! More is better!

shedofjoy - yes you can turn on AO for a light, however there are a couple of issues with doing this.... 1) If you have multiple lights in your scene, the AO given from the light you add AO to will be proportioned to the intensity of the light - so if the light is at 50%, the AO will be at 50% 2) Different materials will require difference raybias' and maxlens - and with light based AO - you are tied to useing just one raybias and maxlen. 3) More often than not, you only want AO on a subset of the materials in the scene. For example, if V3's hand is on her hip, IMO, it looks better with you only have AO on the SkinHip (and not include it on SkinHand). Similarly with clothing - better to have the AO only on skin, and not the clothing. I also don't like have AO on walls or furniture. Using light based AO doesn't give you that flexibility.