Bit smudgy shadows with detailed image

[OzBoz]

I try to render a detailed air filter on a small size to save some time. But the result is as my attachment. Which settings can I change to get the result more cleaner so that the details are more clear. Tried several settings I found but no real change yet.

[nomeradona_cg]

do you have a bigger image OzBoz

[fpedrogo]

Please bigger image and more details of the issues in the render.

Best

[andybot_cg]

If you are just rendering the detail - you could scale up the sketchup drawing. I would guess the irrmap is having issues with objects close to each other. If it's part of a larger image, maybe try a procedural textrue

[OzBoz]

Well that was actually real size I tried to render it. Tried lots of settings and if I render it bigger you get something like this attachment. Still don't understand why it's not consistant with the shadows as it's just a repeating structure. Tried really lots of settings. With the lights and the options. It's renderded in a kind of studio set up. Left/right/top light. Also changed the subdivs in the lights and shadow bias but not much difference.

Although this does look better even when scaled down it's not consequent.

[andybot_cg]

hmm, let me know when you find something out. I guess when I encounter that, I render at a higher resolution until I can't see the problem any more. It has something to do with the irrmap sampling, I just don't know what it is.

[OzBoz]

Yeah I googled a lot and changed so much settings but result is still dissapointing. If I've some time left I might scale the entire model to see if that helps. And it's not that I'm that familiair with the interface and settings but tried lots of things to reduce blotchiness and only render a part of the image to see if it helped. Even at the higher resolutions. You say it's the irrmap sampling, could be.. but I wonder what will happen if I removed the light and used the normal environmental lightning. But takes lots of time to try all settings. Don't have many left.

[andybot_cg]

have you tried "detail enhancement"? I think it's supposed to work for issues like this, I am just not very familiar with the exact settings (and how to keep it from making the render take way too long) I know there's info here somewhere.

[OzBoz]

I did try the detail enhancement but took way more time. Looked up some settings online but no real difference. Did try to remove all lights and turn on GI enviroment/background. That resulted in a picture I would expect. Also tried a combination. Keeps weird it's not consistent.

[stinkie7000]

There's no point in using detail enhancement to compensate for bad GI settings. Post your settings so that people can have a peak at them.

[OzBoz]

Well hereby the settings I used...

[andybot_cg]

There's no point in using detail enhancement to compensate for bad GI settings.

what would bad GI settings look like? Do you think the lighting is not enough? I've had this issue with just the default sunlight. I'm pretty sure it has something to do with having relatively small geometry detail (the place where I saw it was in a frieze with dentils - every now and then, the space between the dentils would be darker.) Just trying to understand your reasoning.

[fpedrogo]

Hi
First I think that the white color is over bright, you need to play with the exposure just a little bit. Second you have a lot of details in that model and your setting are having hard time to properly samples them. I should try with fixed rate as my anti-aliasing and irradiance map + Brute force. Your render will be slower, but if you want to fix the bad GI, you will need a better GI solution and that means more render time.

Best

[andybot_cg]

Hi Fernando - so what is "bad GI" I'd like to understand - is it too little light? Is it some sampling is too low? bad HDRI used? I've seen issues like this with my work too, and I'd like to know if there is something I can do with my lighting to correct it.
Thanks,

Andy

[OzBoz]

Well Fernando, I didn't really knew what you meant by brute forced but as a rough guess I disabled the secondary engine. And below the result. This is the resolution I rendered on (so very low with lots of detail). But lot better result. Even at such a low resolution. Still don't understand why lightcache messes things up doing unpredictable things but ok, this is at least much better.