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View Full Version : Desperately need help on Diamond/jewelry render


mrtep
01-25-2011, 02:41 PM
Hi guys,

I've got a really big problem here that i've been trying to figure out for ages...
what kind of software/render does a website like this use for their renders?

http://www.jamesallen.com/engagement-rings/solitaire/2mm-Knife-Edge-18k-White-Gold-Solitaire-Ring.html

recently, another website is able to do the exact same thing:
http://www.vivodiamonds.com/rt/sdetail.pl?cfg=bpl&cat=8&sku=880&c_gid=0

I've been using matrix plugin onto rhino for modelling and the vray build in to render, the diamond does not sparkle like theirs, and i don't think it's a big secret since another company is able to do it almost 100% the same...

been scalping google and can't get any information at all on anything similar (the diamond's sparkle) and what render engine.

Really need some input! Greatly appreciate it!

InfernalDarkness
01-28-2011, 09:39 PM
What you're seeing here are simply postwork effects. RGB offsets and lens flares, mostly. Chromatic aberration. You can do all of this in Photoshop directly, for stills, or in After Effects or whatever for animation.

But let's say, out of Vray, you have a really nice, realistic, clean render but just want these types of effects? Mask out your jewels as a separate matte pass or alpha channel, and then you can select them directly in Photoshop and run your effects on these sections only. Maybe mask out the metals too, to add shine and whatnot. I tend to spend the least time possible rendering and the most time possible in postwork, to save time. I wouldn't expect to get these kinds of effects directly from rendering in Vray, although it's certainly possible, but may seriously slow down your renders anyway, so it's generally faster to do this in post.

mister3d
01-29-2011, 04:19 AM
What you're seeing here are simply postwork effects. RGB offsets and lens flares, mostly. Chromatic aberration. You can do all of this in Photoshop directly, for stills, or in After Effects or whatever for animation.

Are you sure those aberrations done in post? They look to me like rendered.

But let's say, out of Vray, you have a really nice, realistic, clean render but just want these types of effects? Mask out your jewels as a separate matte pass or alpha channel, and then you can select them directly in Photoshop and run your effects on these sections only. Maybe mask out the metals too, to add shine and whatnot. I tend to spend the least time possible rendering and the most time possible in postwork, to save time. I wouldn't expect to get these kinds of effects directly from rendering in Vray, although it's certainly possible, but may seriously slow down your renders anyway, so it's generally faster to do this in post.

It depends on how long the animation is, what is your machine. As long as you can render it in Vray, I wouldn't fake it, as fake will look always worse. What I would certainly do, is to render masks for further tweaking in post, like contrast, glow and color-correction. Generally, rendering diamonds will render faster than glossy effects. Of course, if you render thousands of frames, maybe it's worth testing doing it in post. But for small turnarounds, you'd better ask the client extra money and upgrade your machine. My machine is pretty old (quad 6600), and the frame time is 13 minutes for a heavy diamond scene. If you have a modern CPU, it would render in 3 minutes. Of course, for InfernalDarkness it's easier to do it in post, judging from his machine specs.
http://img263.imageshack.us/img263/6642/2copync.jpg (http://img263.imageshack.us/i/2copync.jpg/)
In vray, I would use aberration, but would add HDRI for reflection just for diamonds, something like an interior with a blue tint.
http://img28.imageshack.us/img28/1928/diamondsvray.jpg (http://img28.imageshack.us/i/diamondsvray.jpg/)

InfernalDarkness
01-29-2011, 06:02 AM
@Mister3d: Love those diamonds! The chromatics are great... That's certainly something I would also control at a shader level. The lense flares and whatnot in the links he posted are what I meant by postwork mostly. All the extra glows and glares and twinkles. I do see what you're saying though - if you can nail it so clean, it's faster to have Vray handle it and have a better "raw footage" render that you might not need to postwork, of course.

mister3d
01-29-2011, 06:07 AM
@Mister3d: Love those diamonds! The chromatics are great... That's certainly something I would also control at a shader level. The lense flares and whatnot in the links he posted are what I meant by postwork mostly. All the extra glows and glares and twinkles. I do see what you're saying though - if you can nail it so clean, it's faster to have Vray handle it and have a better "raw footage" render that you might not need to postwork, of course.
Thank you. I think the whole trick is using HDRI for reflections plus aberration.

Kev3D
01-29-2011, 10:19 AM
Check out this tutorial for rendering diamonds, it's for Mental Ray but you should be able to gleam a lot of useful information from it: http://mentalraytips.blogspot.com/2009/11/fire-and-ice-rendering-diamonds-and.html

He's got a nice solution for getting the rainbow refractions that diamonds are famous for.

With regards to the glows, I know that a lot of pro jewelry photographers like to use a star filter (maybe a bit cheesy but the clients love it), see if you can find such a plugin for your compositing package.

FreakyDroid
05-24-2011, 11:55 AM
Here's a small animation of rotating diamonds I did to study dispersion in diamonds. Since I don't have a real one to make comparisons, (besides what I found on the internet) you will have to tell me if what I did is good or not. Here is the link:

http://www.vimeo.com/24131337

InfernalDarkness
05-24-2011, 03:38 PM
I think it looks great! Very casuticy, for sure.

Kev3D
05-25-2011, 08:23 AM
Diamonds themselves look great but I think you need to up the quality of your caustics, it's looking a bit low res and noisy to me.

FreakyDroid
05-25-2011, 10:34 AM
Yeah, I rendered it out in low resolution and very low quality, I'm actually quite surprised it turned out the way it did, I was expecting a lot worse. Perhaps when I'm not that busy I can render it out in higher quality. Thanks guys.

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