View Full Version : Proper smoothing?

03-17-2010, 02:43 AM
I was experimenting with low poly models and normal mapping the other day in practice with the upcoming Dominance War and no matter what angle I set the surface smoothing to, I still got hard shadowed edges under basic lighting. Technically, even really hard edged models should be able to show up completely smooth when the smoothing angle is ramped up.

It may have something to do with the normal map and UV edges or it could even have something to do with the lighting. Basically, if anyone has any experience with getting a completely smooth low poly model, please let me know what I should look out for.

I would like to try to enter the competition knowing that I can confidently have a properly smoothed low poly model to show.

Thanks in advance for any help.

Revanto :p

03-17-2010, 04:07 AM
have you got an example image?

AFAIK shadows will still be hard edged (angular) because the smoothing is just a cheat to make surfaces look smooth according to their normals, raytracing doesn't account for it so shadows will be cast from the actual geometry not the smoothed version.

It is common practice to bake textures, normals and AO passes from a high-res character to ensure that the shadows are smoother and more detailed.

03-17-2010, 03:56 PM
Yeah.. that's a little confusing. Can we get an image + wireframe?

03-17-2010, 04:37 PM
the upcoming Dominance War

I surely understand the concept of competition in general. This goes back to the stone age where males fought to get the females to make sure their bloodline would go on but for some reason I just don't get why artists should compete. Sure, the winner will get (money) prizes and might even get women that way :D but in the end art is art and it boils down to personal opinions.
Let's take the 100m dash or or any sport where somebody has to cross a finish line or end up doing something the best. There's no personal opinions involved. If you win the 100m dash you win the 100m dash. Period.

Now let's lay down a few gorgeous strokes using a pencil and a brush. Some people will favor the pencil stroke and others will favor the brush strokes. Aaahh I'm rambling. To me art is art. There's all kinds of art ranging from ugly to mesmerizing. But what I find ugly might be mesmerizing for someone else. Why judge that?

But to get back to the question at hand. I would also love to see some renders and screenshots from the problem you encountered.

03-18-2010, 11:26 AM
You know, I always wondered about this, but didn't think it through. I've always hated that shadows occasionally have odd steps/angles in them when they fall on a 'curved' surface. Curved as far as the shading normal, that is. I feel like a dummy!

It would be nice (but probably impossible in terms of performance) if a rendering engine could actually mathematically account for smoothing angles when it calculates intersections for everything. It would essentially distort the geometry based on the smoothing angles, and would automatically account for shadows, shading, etc.

Of course, I never went past Algebra, so I could just be smoking the ganja... :)

03-18-2010, 01:47 PM
I think that what most others have said here is correct, the ray tracing doesn't account for the smoothing angle very well or at all. Even when you view your model from a low angle to the surface you can pretty much see the "faceting" that will occur in your shadows. As suggested, baking of a high res model over the low res can work, or the more drastic approach, add more divisions in your mesh to better fake the smoothness, but then that's just adding polys you might not want.

03-20-2010, 04:21 AM
I can't actually show you the model itself so I'll try to whip something up to show the issue. However, it seems you understand the issue already.

I'll try to do a render from Poser as well because I noticed that in Poser, smoothing is more intense. Also, I think that in Poser, the normal map overrides the smoothing of the geometry to an extent.

If I don't post something up soon then it means I've been distracted with something else I need to do. But I appreciate peoples' feedback so far.

Revanto :p