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View Full Version : 9.5 dispersion vs bump


Ernest Burden
09-24-2005, 09:22 PM
I've never used 'blurry' effects, always used my old-school method of using a very small bump on a reflective surface. That, too, can be slow. But I like the results. But with the newly 'faster' blurry (now called dispersion) I figured a test was in order:

Never mind the overall GI and lighting, this is just about making the floor look good.

floor with a very small noise bump, no dispersion mins= 2:12
http://www.oreally.com/temp/reflect-A.jpg


now with no bump and dispersion to match as best I could 3:10
http://www.oreally.com/temp/reflect-B.jpg


finally, both the bump and dispersion 3:11
http://www.oreally.com/temp/reflect-C.jpg



I prefer the bump. It may be too strong in this example, but overall looks more natural, in my opinion. Other opinions?

tcastudios
09-24-2005, 10:28 PM
At a first look, bumps look more "painted". You know the way old wooden boats could look. Dispersion look more, eh.., polished or spray painted.

Cheers
Lennart

ThirdEye
09-24-2005, 11:36 PM
Have you enabled AA best? If not do it and post the pics again, that'd make a huge difference. So far i prefer dispersion.

destro80
09-24-2005, 11:49 PM
Would be good to see the dispersion again but at a lower level. I think a hard wooden floor would have a shaper reflection (at least where the reflected object is close to the reflection). Also with a bump map to put a groove between the planks of wood to see how well the dispersion and bump maps work together.

Per-Anders
09-25-2005, 01:41 AM
if you want your dispersion to look as bad as the bump, simply lower the accuracy and number of rays (same in the old dispersion since 7), this will of course speed up the dispersion a great deal.

Ernest Burden
09-25-2005, 03:33 AM
I think a hard wooden floor would have a shaper reflection (at least where the reflected object is close to the reflection). Also with a bump map to put a groove between the planks of wood to see how well the dispersion and bump maps work together.

There is a groove between planks, though its thin (difuse channel = affect reflection).

I could have the floor shinier, I just like it like this. I'll test is higher, though.

if you want your dispersion to look as bad as the bump, simply lower the accuracy and number of rays (same in the old dispersion since 7), this will of course speed up the dispersion a great deal.

I don't think the bump version looks bad, I think it looks natural while the dispersion looks artificial. Even where it is near the table legs it is still blurry, while the bump one is much sharper. As for the dispersion setting, I just used the default, only adjusted the strength to match my base image. I'll try what you suggest.

Ernest Burden
09-25-2005, 05:16 AM
As suggested, I re-tested at AA=best. That took a while. I won't be using that setting again until I can buy bigger computers.

I also made the floor a bit more reflective and reduced the size of the bump so it would make a smoother surface. I enlarged the planks (by the way, done without maps, just shaders). Now the render times are about the same, though that is probably the AA. They also appear almost identical now, though the few parts where they are different, I still prefer the less-perfect look of the bump. But to each his own, I'm not trying to sell anyone of anything, just looking at two ways to do the same thing.

bump, 23:00
http://www.oreally.com/temp/reflect-D.jpg


dispersion 24:05
http://www.oreally.com/temp/reflect-E.jpg

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