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I have looked at Image Based Lighting for a long time, and being an avid photographer I believe I understand a little of capturing location specific lighting with a chrome sphere. What I would like to know is what are the best steps in determining when and where this can be applied in EIAS3D to achieve better lighting solutions given that I can't capture lighting for all scenes.

 

Of course I may completely misunderstand IBL which maybe why I haven't used it earlier.

 

Michael

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Hey Michael and Joe,

 

Hmmm, when and where iBL can be applied.  I can answer your question first Joe.  The presets that came with V9 are just set too high in the GI Sky Light Settings.  For Example, if you select the Golf Course A, you have to set the intensity to .2 and it will work fine.

 

If you want to drop your model into a photo scene or if you want intricate reflections and refractions are uses for ibl.

 

At it's core Image Based Lighting is just lighting the scene with one image.  It gets complicated because people usually attach a matching reflection image and a backdrop image and maybe a sun to make directional shadows.  I see more people using one image for everything versus the three different ones.  ONE big difference with other lighting, specular highlights usually are flattened out which is why people add a sun and lights just for specularity. (there is GI glossy for this as well).

 

I got an understanding by looking at Ian's video in the gallery under Rendering, Rotoscoping.

 

This might help http://www.intuitionusa.com/1/ibl.png

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Ok, first problem... I don't have any presets!? Golf Course A... where do I find that? It's not in the EI Presets folder in v9.1. Were the presets issued with v9.0 and not with v9.1? If so where can I get them from?

 

Second, it refers to them as .ibl files but I have .hdr files, what's the difference and how do I create .ibl files. When I put all my .hdr images, that I have collected over the years, into the EI Presets folder, I can only see one of them and none of the others.

 

It appears as the simple things a difficult enough to figure out, let alone using them!

 

Sorry but there is a big disconnect here!

 

Michael

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Hey Michael,

 

I suggest starting just setting up an image based lighting system by hand at first.  Ignore the Environments palette and all the presets that came with 9.1. Check out ian's rotoscoping video in the Rendering section of the tutorials.  You could set up an image based lighting system with "one file".

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one other thing id like to add to this conversation from people who do what I do for a living.... stylized graphics and visual effects etc...   I'm interested in how these settings may allow me to achieve unusual, "cool" looking 'effects'.    Sort of the opposite of reality...  also... can an ibl  be animated?  

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http://www.hdrlabs.com/news/index.php

 

I found this to also be a very informative site. Buy the book, it covers everything.

 

Michael, IBL sets or sIBL's are a collection of; environment map, reflection / refraction map, and backplate. All derived from the .HDR image.

 

The HDR is a "layered" single file containing a range of exposures. From white to black. (but not as we know white and black on paper).. We can capture more and the human eye can see more expose range than can be put on paper.

 

So if you download the hdrlabs free software, you can put an hdr image into it and it will produce the collection of images as stated above. (environment map, reflection / refraction map, and backplate). Plus if you want, it will produce a colour correct sun. That's your sIBL file.

You can adjust maps so no sun is needed, but they must be really good maps.

 

You can't really just use the same HDRI for all the slots, they need to be altered to suit (lot's of explaining why to be inserted here). The hdrlabs software does it for you. The software only runs on WIN but of course the maps it produces are fine for MAC as well.

 

So then you bring the sIBL (through environment) into EIAS and you have everything in the correct "slots". .env in the HDR slot, .ref in the raytrace global slot, backplate (,jpg or ,tiff or ,tga.. up to you) in the rotoscope tab and a colour correct sun as well.

These are all linked automatically. Go to the texture tab of any of the maps and rotate to you desired position. Most good maps will have the sun orientated correctly.

Go to a top view and rotate, the line points to the sun. You'll see the map rotate in the camera view, and all other maps will follow.

 

That's the basics of it. "Tuning" maps can be done in the "special tab" of the texture window for any map. I don't do this very often, I prefer to "tune" in photoshop, but it can be handy.

 

Once you have a few sIBL sets in place you can chop and change your lighting in seconds. Literally a couple of clicks.

 

All HDR has it's nuances so be prepared for some varying results initially.

 

Personally I don't use the GI HDR slot as it does not bounce the HDR light. It looks pretty good though. There are other ways to use the HDRs to light other than the HDRI slot in GI.

 

It is a journey but well worth the effort to get it working right.

In my opinion EIAS does it well.

And by the way, it flippin fast! To render. And yes it can be animated.

 

And dare I say it. Working in Gamma 2.2 makes it a whole lot easier. hdrlabs website and book explains why.

 

All the best.

 

Just extending on all that. Another way to light with an HDRI is to map it to a sphere and use that as the light source. Instead of the GI HDRI slot, turn it off.

So the sphere is a light source with a light "attached" but the map applied to it does the lighting. (keep the segments of the sphere / dome low as each is a single light source) Add a parallel sun to taste. Especially for shadows. (you can "tune" the HDR in photoshop to produce shadows very well but that is a lot of info to put in here. But.. it makes rendering very fast as there is no virtual light source.

That is the "real" way to get HDRI lighting, bounced as well! Looks great when balanced correctly.

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