CGTalk - Help with artifacts in Brazil

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loden

01-20-2003, 11:09 PM

Hi everyone!
someone could help me with this artifacts that came out when I try to light my scene with Brazil Skylight? It's strange because I'm sure isn't a problem with sampling: I try to push it untill 50 but the problem is still there! I noticed that changing the contrast from black to white those artifacts get bigger. But, more than black I couldn't go:-)
The geometry is a simple poly with some inset/extrude, nothing special.
I attach a sample of the rendering: in the left with Max lightTracer (no problem here with geometry) and in the right the Brazil Skylight.
Thanks!
Bye

Bluplet

01-21-2003, 01:05 AM

set the minimum shade rate to -1 and see what happens

Khepri

01-21-2003, 09:58 AM

increasing the viewrate(shade-rate rearly needs to be increased), enabling image sampling, or set different smoothing group for the object(if it is 1 object with modeled details)
.

good luck and keep us posted
:)

loden

01-22-2003, 03:31 AM

Thanks guys!
I try to change some settings but....the problem are still there:-(
I post my settings:

Image sampling:
Min: 1
Max:2

Shade rate:
Min:-1
Max:0

View rate: 30

With this settings and also changing the smoothing groups (yep, it's one big mesh for the building) the only things that changed was the shadows, now more smooth and nothing else...Maybe I'm wrong somewhere! I try adding a direct light, this only sharps a little the area, but don't fix my problem!:-(
Any idea?
Thanks anyway!!
Bye

jeb

01-22-2003, 08:21 PM

also take a look at neal blevins undersampling notes.

Khepri

01-22-2003, 11:09 PM

can you post an updated image?

that would be a great help

thnx

loden

01-23-2003, 02:51 AM

Hi!
jeb Neil Blevins is one of my favourit artist, I read al his tutorial also the one on undersampling and its really great!
Anyway, I got it...more or less. I push the shade rate to Min1 and Max1 and the problem is less visible now; checking the "lock to image ratio" setting is perfect. But this will increase a lot the rendering time! Here (http://lodenlabs.supereva.it/new_t.JPG) you can find an update of the rendering. I've made a sample scene that you could find here (http://lodenlabs.supereva.it/prova.zip) for you to test: it's a simple poly with really near extrusion/inset. Once opened the scene, just press F9 and render: in my pc between the extrusion appear the same problem of my original scene. Take a look to settings: view rate is low but I tried setting 60 and things don't change. The only way is to set the shade rate to 1 and 1. I hope I'm wrong and that you could help me to find a better way.
Thanks guys!
Bye

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