OTOY Forums

Hey guys I've got a some questions regarding the diamond material. I'm rendering using the Rhino plugin but I wanted to post this here to get some more eyes on it. I've been running tests using a range of HDRI from the Lightmap plugin and I'm using a few IES lights in the scene as well. The problem is it seems like I can't really control the colors being refracted inside the diamond or the color of the diamond in general. Mostly I'm just getting these yellowish washed out diamonds that aren't really giving me what I need.
The last image was made using VRAY, its more what I'm going for and I'm using a png image of a diamond in the refraction slot to control the colors refracted around, nothing but crisp whites and blues really. Is there a way to achieve similar results in Octane? Any input would be greatly appreciated. Thanks

I can't speak to any of the stuff you are asking about (didn't even read it all), as I am not one of the many jewelry guys around here... but...

Me and wifey were at dinner last night, in a nicely lit steak house. She all of the sudden started going on about how incredible her rings looked... I said, "yeah babe, diamonds sparkle real nice and look that much better when there are tons of little light sources (prolly halogens in this case) all over the place, in a subtly lit room, that has a darker ceiling and walls..."

... I am looking at your HDRI, and I'm thinking that long lights like in your HDRI is not the best way to light diamonds, based solely on my observations of the world around me, like above. I am not formally trained in lighting design or commercial photography.. just tossin' this out there.

Hi,
what are your kernel and camera imager settings?
Are you working with linear response and gamma 2.2?
The illumination has a great impact as Frank pointed out, so could you share a simple scene to play with?
ciao beppe

Hey! maybe you should add some dispersion to your refractions!

Hey guys thanks for the input. I'm running my HDRI lightmaps at a gamma of 1 because this is the recommended setting from light map, http://help.lightmap.co.uk/hdrlightstud ... octane.htm I also got a email breakdown from them if anyone wants to read it. The forum is not letting me upload my hdri maps but they are mostly dark backgrounds with various lights. Adding IES lighting does improve the diamond reflection but really doesn't let me control the color of the diamond which is what I'm really after. I've been working in live mode a lot to test different light sources. The diamond material itself has a Dispersion coefficient of 0.044, and an index of refraction of 2.419.

I've been rendering using PMC Kernel

Ray Epsilon at 0.0001
Haven't messed with too much else in the Kernel settings because I'm still learning my way around things and haven't been able to dig up any optimised settings for this, same with the camera imager. Definitely open to suggestions. Thanks!

Hi,
you can share a simple scene in .orbx format so all the assets are packed (also HDR)
Anyway I guess that it's only a matter of finding the correct Imager settings for your taste, start with switching from agfa Gamma 1 to Linear Gamma 2.2 and, set the correct exposition/saturation, and slightly reduce the gamma until you find a good value... just an idea
ciao beppe