What makes it real????

[STRAT]

heya guys.

 

i posted this question up on another forum last year some time, but i dont think ppl really got my gist. so i thought i'd post up the same question here for discussion to see what your take on it is. here goes -

 

Realism, what makes it real?

 

when you see a cracking cg image you can nearly allways tell it's cg, artificial or a rendering, weather GI or no. but when you see a photo, weather it a small, tiny, out of focus, crappy grainy thing, or even the blandest plainest photo you ever seen, you know it's a photo, it's real. why???

 

i personally think it's got basically nothing at all to do with modelling abilities and texturing, but rather it's ALL down to GI and radiosity and lighting, well, maybe 99.99999% it is.

 

photos and things in real life, no matter how simple, have natural lighting to them which our brains automatically take in and take for granted. we just know. Computer renderings, even with clever GI and lighting just dont have that 'something' our brains take for granted. Even if the real photo has nearly no lighting in it atall, well we still know it's real, why? well because no 2 parts in the photo/subject matter will EVER have the same exact 2 colours - the chaos theory, and because of this fact our brains automatically detect this without our even being aware of it. its very difficult to exact this effect in CG.

 

to conclude, i appreciate modelling and texturing skills do help to percieve reality, but, imo, at the end of the day it's lighting that clinches it.

 

what do you lot think?

[Wolf]

your right strat, the lighting is a big thing i look for when im not entirely sure if its cg or real, but i have a feeling that with all the new gi renderers out now, it will be harder to pick out the cg ones

theres lots of other little things that can stand out, that even GI cant hide.....

 

what i look for, if im not sure if its cg or real.

 

Lighting

I look for hard to soft shadows, and light darkening in corners, and under furniture.

and im just starting to look for tell tale grain from gi renderers such as brazil, or the dirty undersampled images from renderers like vray

 

Textures

Tiling textures is a give away, and not enough people make their textures high res enough.

 

Sharp edges

Its easy to model with extrudes, alot harder to make soft bevelled edges, so i often look at the geometry and the the super sharp cg edging.

 

Chaos

multiple objects that are identical in modeling and textures.

its a good idea i think to make several models, and texture each one with a different texture map.

i remember the maya "is it real or cg" test, and the easy ones to spot were the ones with the same objects cloned, like the nails.

 

wear and tear

even the newest architecture has some wear and tear on edges and corners, so adding noise to certain edges may help to move away from perfection, and more towards realism.

(although architectural visualisation, may not be the place to add wear and tear)

 

Reflections

Fresnel isnt used much at all on glass or water, so its easy to spot when someone hasnt used a fresnel shader, and the reflections and transparency look to uniform.

 

these are the things i try to look for

 

maybe we can all post a pic, and everyone can guess if its cg or real.

[nisus]

Hi all,

 

I'll just add a few extra thoughts.

 

Highlights:

- How many are they? (I hope everyone knows the give-away of spotting more than one sun in cgi)

- What's the shape of the highlight?

- Is it regular?

 

Scene setup:

- It's a bit like Wolf's chaos, but even if you use several models their relative positions in space might tell you a cgi-hand placed them.

 

Dirt:

- not only wear and tear but all kind of rubbish that floats around

 

Trees/Grass/Shrubbery:

 

 

And of course any errors (like wrong bumps) and impossible things (zero gravity etc.) but I think these won't be a problem to spot.

 

rgds

 

nisus