floor wall ceiling and whats in betwen

Heya guys, theres a thing iv been thinking about a lot. In games, buildings standing on the ground, where the building meets the ground, or walls where it meets the floor/ground and ceiling, often end up looking very artificial and can destroy the illusion that you are trying to make. do any of you know why this happens?
and do you have a good way of fixing it?


just found a few images for explanation:
http://forum.unity3d.com/files/picture_14_108.png
(image is by terransage and scavanged from the topic http://forum.unity3d.com/viewtopic.php?t=3954&start=15)

If you look at where the chairs are standing, and the corner


http://static.computergames.ro/cg/assassin/images/halflife2/halflife2-060.jpg
this one (from HL), the wall to the right, im not quite sure why its not quite as visible here though


http://www.fragz.ca/images/games/screens/halflife2.jpg
and this image from HL2 has somehow magicly fixed most of it. its only really the kerbstone that is breaking the illusion and still, it isnt that bad.

so my question is, what differs so much in these 3 images. and what excactly is it that creates the feel of artificialness?

 

It's called polygon budget, and maybe be production time. To make walls look like they do in real life would require a lot more polygons, and more effort to create and texture effectively. Basically were wall meets floor isn't a perfect right angle. There is slight variations in angles across the whole join, there is dirt build up in joins, there is unlevel floor joints, wall joints etc. There is slight changes in diffusion caused buy slightly different thicknesses of paint, plaster, dirt, oil build up, etc, etc. All these variables are very hard to model, texture - to control. So one compromises. :wink:

With that said I believe a bit more work could be done to solve those issues, the first one is to use a dedicated 3d painting package to blend seams, and use proper weathering techniques that the plastic model builders use. But that requires time spent doing good UV mapping!

So I guess it comes down to cost benefit analysis.

But the number one thing to remember is that there is no such thing as a perfect right angle in nature. And human eyes are hardwired to pick up patterns... part of our early survival plan on the African savannas! :wink: So as an artist we are fighting an uphill battle for realism, especially in realtime graphics.

Cheers.

 

A "cheap" trick to make the blends seem better is to run some ambient occlusion on the lightmaps, so both floor and wall darken a bit where they meet. Doesn't really solve the problem, but does make it less noticable

 

Thanks for the input guys, what iv normally done is put shrubs and stuff to break the line, or if its indoors adding a fillet (like there normally are, wierdly enough a fillet often fixes the problem, but im looking forward to having computers so powerfull enough to make it 100% realistic (in Virtual Reality =P )