ambient occlusion bruising?

H

hertzcastle

0
ambient occlusion bruising?

hi!
has anyone found problems with ambient occlusion artifacts?
i find that if there is a sharp edge or if i put objects too close together strange "bruises" appear on the object behind. check out the ears and wing edges on this render(attached).
ive tried messing with the AO settings but nothing helps!!!
any ideas?
x
 

Attachments

  • bruise.jpg
    bruise.jpg
    55.4 KB · Views: 531
the settings depend highly on the file, each needs its genuine finetuning, so maybe you can provide your file and i can have a go at it later.

- archie
 
I get the same issues. I have had some luck with increasing the materials emissive a touch and adding a very low power area or ambient light but I have found its a bit of a lottery whether you get artifacts or not. In some cases increasing the samples has helped and in others not.
 
The bruises by the wings meeting the wing membrane at the top appear to be subtle indentations or no? Another light might flatten the appearance but the bat design for Halloween looks good.
 
This is quite a problem. For me its particularly bad when rendering models without textures/materials etc... Never had this issue in 3DSMax.

P.s. Cool bat by the way :D
 
Thanks ZooHead - good info!
I just wrote a two or three paragraph response but then had a not-logged-in-fumble. After logging-in, my browser lost the text :-x
So... oh well.

--Shift Studio.
 
Last edited:
Shift Studio said:
Thanks ZooHead - good info!
I just wrote a two or three paragraph response but then had a not-logged-in-fumble. After logging-in, my browser lost the text :-x
So... oh well.

--Shift Studio.
Click to expand...

I've done that before, I started pasting a
copy into the Notes program on longer posts.

​
 
ZooHead said:

I've done that before, I started pasting a
copy into the Notes program on longer posts.

​
Click to expand...

Yes good idea.

Now, what did I say...

I wanted to know why you chose Rmin = 0.5 - I've never played with it.
And how about Irradiance Cache Error = 0.15, the default, when and why might someone change it?
And what is 'Irradiance Cache' anyways?

And I mentioned that I've experimented with 'Max. ray length = 0.1, 0.2, 1.0, 10' as suggested by Frank in his backlight scene tutorial.
I don't know what 'Max. ray length' really means though - Anyone?
I do know that low values help light up a backlit object.

Enough rambling
Thanks for any further info.
--shift studio.
 
Shift Studio said:
Yes good idea.

Now, what did I say...

I wanted to know why you chose Rmin = 0.5 - I've never played with it.
And how about Irradiance Cache Error = 0.15, the default, when and why might someone change it?
And what is 'Irradiance Cache' anyways?

And I mentioned that I've experimented with 'Max. ray length = 0.1, 0.2, 1.0, 10' as suggested by Frank in his backlight scene tutorial.
I don't know what 'Max. ray length' really means though - Anyone?
I do know that low values help light up a backlit object.

Enough rambling
Thanks for any further info.
--shift studio.
Click to expand...

I lower the Rmin only when the artifacts appear and just enough to eliminate them, the Planet 51 model needed it.

I don't know enough to answer your other
questions, someone else can help I'm sure.

​
 
You must log in or register to reply here.
Back
Top