What parameters should I change to fix this render?

[panofish]

I have been working to resolve a problem... I'm sure someone here can fix.
If you look at my rendering you can see the flaw in the back corner edges of this glass object. There are hot white spots that did not antialias like other areas did. I've tried increase material depth, subdivisions and rendering subdivisions, antialiasing parameters... but I haven't made any noticeable improvement yet.

WHAT parameter(s) should I change to improve this flaw and any other flaws in the image? THANKS!



Here is my model.
http://home.comcast.net/~panofish/glass1.zip

[vlado]

You need to check the "Clamp output" and "Subpixel mapping" options in the Color mapping rollout.

Best regards,
Vlado

[panofish]

Very interesting

Thanks Vlado!

That definitely improved the image, but now it seems flat in those problem areas. However, when I checked the online manual (in a futile attempt to comprehend subpixel mapping and clamp) I stumbled onto the "universal settings for vray 1.5". So I tried that... and the image looks even better still. It took much longer to render with "universal settings", but the image looks best. The universal settings have "clamp output" and "subpixel mapping" OFF. That makes me think that your suggestion was a comprimised shortcut. I wonder if there were other parameters I could have changed that would have been more specific to solving my original problem? I lack the experience and understanding to solve this riddle

[nagboy]

Cheers,

Had a look at your scene, done a few changes, rendering times are not the most friendly about 10 mins on my home machine. I suggest remaking the scene in a proper scale with proper lights (btw, the vray light is not a directional light, it matters where you put it...), a vray camera with exposure. Also, turn off optimise on the shape, it destroys nice details in the shape...

Below are rendered image, photoshopped and the scene...




curves+bloom+duotone

file:
http://www.nag.no/glass2.max

hope this helps...

[panofish]

wow

I think I love you nagboy and I'm not even gay.
That is very awesome and very appreciated...
I think I coulda spent all week on it, and never got those results!
I hope I can repay in kind some day.

I am going to render it myself now and see if I can discover what kind of changes you made.

THANKS!

[panofish]

Still confused

I loaded the glass2.max file nagboy posted and rendered.
I can't figure out why my render is not the same.
It appears that the caustics are not working, even though they appear to be enabled.

What gives?

[RErender]

Probably different system units? Or different versions of V-Ray

[panofish]

Thanks ReRender...
I don't think it's the system units, because I tried many other units and max complained of a mismatch... so I checked rescale and several permutations and got some differences in the render, but I didn't get the same result as nagboy.

I am using vray 1.5 RC3.

What version of vray are you using nagboy? What are your system units?

[nagboy]

try to change the caustic thing from "from file..." to "new"

[panofish]

doh!

In the inimitable words of Homer Simpson... DOH!
I saw that before, but I didn't take careful note of it.

That fixed it...
Now I see why you were saving the caustic map... because my render just took 35 minutes on my older machine.

THANKS again Eivind Nag!

[nagboy]

always check the vray log window if something like that happens, probably a big fat red line with warnings it cant find the missing file.

[panofish]

Thanks

Thanks again Eivind, I feel pretty stupid for not having figured that one out on my own. I guess I had tunnel vision on this one.

[paulison]

so basically there is no fault with vray?

[panofish]

No fault with vray... just my fault.