question on photorealism

[Tudor]

Texture, light, shape...

All of it.. You can't single on of them out. If I would have to pick the most important one it would be light though.

Texture and shape can vary, but light always behaves the same in reality.

[Steve Warner]

I'm going to agree with Tudor that it's all three, but I'm going to disagree and say that the most important thing (if there really is one) is texturing. (No offense Tudor!)

Texture is what tells us what material the object is made of. Is it plastic, or metal? Is it soft, or hard? Is it transparent or opaque? Lighting is seriously important, but I think we've all seen poorly lit photos. (My mom has boxes of them in her garage.) That doesn't mean the objects in the photo look unreal. But if you see a picture of a lake and the water has no reflectivity at all, it simply won't look real, no matter how well lit it is.

I would recommend going to Amazon.com and search for the New Riders books "Digital Texturing and Painting" and "Digital Lighting and Rendering." And also be sure to visit Leigh's tutorials here on CG Talk.

Hope this helps!

Steve

[psil]

Yep, I think the realism is mostly in the texturing. Then you've got to light the textures which is trickier than you might think at first.

Simple - even inaccurate - models can fool the eye at first glance with the right textures and light.

[damon579]

yeah... ive been wanting those books but just dont have the spare $$ :hmm:

thanks for the info guys. :D

[dark_lotus]

don't forget that you can actually incorporate lighting into texturing (photometric modelling for example).

On the other side, a model can be rendered with GI (global illumination) with no textures and still be photorealistic.

I think what makes something photoreal is the ability to get it close enough to that you can walk up to your average joe and he can't tell its cg.

Everyone is different when it comes to realism. Some are more picky than others. The hyper-picky ones are never satisfied.

[damon579]

personally i consider something that has the look and feel of a snapshot to be photorealistic. in the "post your best work" thread in either WIPS or finished work there was a image of a puzzle of mickey mouse and various other objects laying on a table. you could tell it was cg after looking at it for a few seconds, but it was a georgeous image. that, and the wooden train post that had the colored shadows. that looked great as well :)

[leigh]

Originally posted by dark_lotus
On the other side, a model can be rendered with GI (global illumination) with no textures and still be photorealistic.

I disagree.
I for one am sooooo sick of GI renders.
The whole idea of global illumination is to simulate real world environments, not to light your model with a falloff colour.
And a model that had absolutely no textures on it cannot, technically, be photorealistic because nothing, and I mean NOTHING, in real life has consistent, flat colour ;)

[psil]

Originally posted by Leigh


I disagree.
I for one am sooooo sick of GI renders.
The whole idea of global illumination is to simulate real world environments, not to light your model with a falloff colour.


Yeah, me too. Most GI renders make things look like realistic clay on a dull day. Best to add some direct light, i reckon

Damon - if you're relatively new to CG, I'd also check out Bill Fleming's books. I personally didn't find 'Digital Texturing and Painting' very helpful. Rather than telling you which buttons to press, he tells you to smell your textures...yeah right...

As Dark Lotus sez, you have to fool 'joe public', not other CG artists - they can all spot CG renders from a mile away.

[Steve Warner]

With regards to Digital Texturing and Painting, you should probably know going in that it's not going to tell you what buttons to push. Psil, you called that one. I'll have to check out Bill Fleming's books. But the Digital Texturing book isn't a total wash. It really spends a great deal of time training your eye to really see what is there. I have a background in print design. After awhile, you don't see colors as red, or blue. You see them as mixtures of CMYK colors. It's the same way with textures. The Digital Texturing book won't tell you how to use LW's tools. It will teach you how to look at an item and tell why it looks that way.

With regards to photorealism, I think it's much easier to fool someone with a still. If you're trying to achieve photorealism in your animation, that's an entirely different story. I personally have yet to see see a CG animation that looked completely real. It's like the tools aren't quite there yet. Every CG animation seems to have this otherworldly weightlessness. I'm thinking of the recent Spider Man and Star Wars movies specifically.

Just my 2-cents. :)

Steve

[NanoGator]

I think lighting is the most important aspect of photo-realistic renders. The reason that photos of textures look so realistic is because they are capturing some effects of real world light.

I think the most important aspect of good lighting is to realize that lights actually have area. In LW (and every other app out there that I know of...) a light is infinitely small. In the real world, lightbulb is 3 or so inches across, with light emitting every step of the way.

That's why GI renders strike our eyes so much. The shadows look right because, just like in the real world, the object is surrounded by light. I am so glad that Eki created 'Overcaster'. It's because of him I understand that concept as well as I do now.

Don't get me wrong, texturing is very important too. Surfaces react to light in different ways. But no texturing can save a bad lighting problem, unless of course the texture actually has accurate lighting effects with it. :)

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