This is part of a larger scene I’m doing for the Elysiun weekend challenge #88 (“jewels” theme):
I have an ambitious scene in mind, so this would just be a small part of it if I get to create everything as envisioned. Two layers so far, all procedural textures, Blender 2.32 with ray tracing. Jpeg compression artifacts present. Lots more to do. I’ll post an update when I get the chance.
Everyone have a good weekend 
RobertT
Robertt, how can you obtain so good textures ???
Of course you may want to wait the end of wc for giving explanations
I tried the same and failed miserabily so far.
By the way, from the wire, even if the overall shape is quite good, the cut is wrong. Theere is a fixed formula for round diamonds with 58 facets mixing triangles and losanges
see
table diameter should be 58% of girdle
crown height around 16%
pavillon height 43%
This is for small ones but even the bigger diamond follow this formula with facets subdivised further
Other cuts (pear, losange) exists but are quite similar in the facets scheme
Thanks for the info, lukep. The materials were difficult to get just right.
BTW, how did you manage to get a face with 8 points in Blender? (colored in blue):
RobertT
It’s actually 4 faces whose boudaries disappear in optim mode.
btw, the 58 facet rule does not include girdle and cullet is counted as one
before he answers, i’m guessing he started from the top, and made a circle with 8 verticies.
then made the rest of it.
but started as the circle.
mystery
well it was a good guess anyway 
Hi, mystery00. I had asked because Blender can only have 3 (tris) or four point (quad) faces.
I can’t duplicate the disappearing faces (bug?) in optimal mode (Simple Subdiv or Catmull-Clark). What version of Blender are you using lukep?
BTW, I did a little more research (for example, this site was a little helpful) and made a couple of other diamonds. The material settings for this shape aren’t quite as good and require further tweaking. The second one seems to me more interesting than the first more “correct one” on the left after a smooth subdivision (80% smooth):
Back to work on the wc wip 
RobertT
I use standard 2.32 on Os X. My picture was not subsurfed and with the fasterDraw button pushed. Wire added with draw extra in anim panel.
From what I can see, your IOR is not setted at the normal diamond value of 2.45. If the round brilliant cut is fixed, it’s because the internal refractions make the maximum brillance in this case.
Subsurfing like you do is a fay to fake it, but it’s possible to obtain the correct pattern with IOR, good cut, and no subsurf, I’ve tested it. Although I wont show it because my textures sucks and it is not worth of it. I obtain the pattern of internal reflexion but no brillance, and if i get the brilliance no pattern. Good catch 22, make your choice. 
WOA, Robertt!!!
Once again, marvelous work.
I’m triying to work to get a pic for this Weekend contest, but when I saw yer entry, I said myself “What for??”
And best of all, as allways, is the speed you work at, and the results you get. Amazing, simply amazing. You have to build some tutorials to explain to us how you do the work you do.
Thanks! Oh, but don’t think you’re getting out of the wc that easy, elGordo 
I definitely want to see your completed entry by Monday, so get back to work
I periodically mention the fact that I don’t enter the wc to win, just to get better at Blender and create something I wouldn’t normally make, so, in answer to your question “what for,” for me the answer has always been “for yourself” (if not also for Blender and Elysiun and its community, to get better, have fun, receive constructive criticism that helps you along, and to interact with cool and creative people 8)
RobertT
Cool. I’d like to own a Mac some day.
I set it at 2.42 because a number of websites stated that was the IOR for diamonds, but you may be right. All that’s true is not necessarily online. Also, I’m using fresnel, translucence with shadows, and light cloud textures with several ray lamps lighting the scene. I wasn’t really going for a diamond at first though, just something shiny or gemlike I’m also using cubes with halo materials in the second layer to enhance shiny spots.
I’m not subsurfing though, I just subdivided. When I said “smooth subdivide” I meant the W key and Subdivide Smooth, which is for the diamond on the right which I might not even use in my scene.
Yes, it can be difficult trying to replicate the real thing using just things like the real IOR, etc., because the object you make doesn’t necessarily exist in a perfect void in a scene (unless maybe you constrain it to its own layer, use layer only lamps, etc.), so the presence of other objects and lights (especially if you’re doing a radiosity render) can alter the visual properties of objects, including things like color, reflectivity, specularity, and shadows. Getting everything to render harmoniously is its own art.
Well, good luck with your entry. I look forward to seeing it.
RobertT
wow. that looks great robertt.
hehe. i just ordered my PowerBook G4 today through apple.com. I am so ready for it to get here. I have been a life-long PC user, but I am going to Illinois Institute of Art this October for Web Design, and wanted a really great computer, so I bought a Mac. This home comp of mine has a 900 MHz P3 processor with 128mb RAM. My Mac will have a 1GHz G4 processor with 512mb RAM. I will so be able to render faster.
Hey, that’s great Jay! Sounds like you have some exciting times ahead Rendering fast is a good thing. Plus, if you have two systems side by side like that you maybe can do twice as much blending 
blend while the other is rendering… double the fun…
RobertT
actually, i live in southern illinois, so i will have to move to shaumburg (near chicago up north). i will only have one system up there. i will be rooming with 3 other guys, so i may be able to snag a computer from one of them for a while.
you saw my Giga’s Valentine pic, well Giga and Jay-Man and the other Jay-Manian characters will soon be made into a few short movies. i am heavily working on the modeling and lighting techniques so that i can work on the first short this summer on my mac. i share this home comp with my mum, dad, and my twin bro. to render anything that takes more than an hour is almost out of the question. so i will work on animation this summer. that being the time that i am not out partying with my senior friends before they all leave me. 
I started with the AppleII, and dreamed a longtime of a mac. But once I had one, i will not even consider anything else for home, even in the times were intel PC were far superior. the real value is not the comp but MaOs, and now there is an unix under the hood, it’s even better.
shouldn’t make a big difference. The 2,45 (was even 2,4517) comes from a jeweler site. As you where not getting the full pattern I was thinking you were way below in IOR.
I had always been pretty good at modelling and a little below with texturing in POV. With Blender it is worse, because the texture system is much different and in many cases react the opposite way that I want. I really miss the filter/transmit treatment of alphas which allowed in many cases to resolve surrounding problems. On the contrary, you have more control on specularity in blender.
It’s not that blender is inferior, it is only different but i will need long bad renders to be at ease with it.
Don’t wait too much on my entry, result is simply bad so far.
But I work on it
I just hope correct results will not come past deadline like last week
lukep: yes, the unix capabilities are what make it very interesting. I use Linux too, so once you get a taste of that power and flexibility it can be a pain go back to simple little windows …unless you have cygwin… which I do
Well, another piece for the scene… not aiming for true to life gems or gold or anything at this point (I have to step up the pace now)… just shiny happy stuff for the scene. This will not be as large in the final render, so this is sort of a closeup:
I’m only using procedural textures for this piece. This… whatever you want to call uses a marble texture with low turbulence (3.8 ) that’s set to SizeX & SizeY:20 which, along with cube/object mapping, helps establish the swirly nor on top of the rough gold surface produced in the preceeding texture channel (also a marble texture) which follows another that has a cloud texture to provide spec and color variety.
lots more to come…
RobertT
Hi, nice jewels there.
I’m an old-time 3dstudio max user that have switched to blender
just recently, your challenge is fun - I need to see if Blender can
be productive in an short time-span so I did an One-Hour speed
modelling & materials test.
All done in Blender 2.32 - One hour.
/JoOngle
Thanks, JoOngle! Nice render! You made the right choice Blender can help you be INCREDIBLY productive in very short time with time to go back and tweak.
If you get the chance to check out the cgtalk.com speed session threads (in the Modeling section off their home page) you’ll eventually see some stuff I did in speed session time (limited to 3 hours). A couple of recent examples include this one for the recent “posthuman” theme:
(approx. 30 minutes to make)
and this one for the previous theme, “cloth and draperies study”:
(approx. two hours to make)
Blender has SO MUCH POTENTIAL it’s not funny (but it IS fun! :D)
Thanks for stopping by. I hope to see more of your work!
RobertT
Another item for the scene, a crown…
For this one I’m using the wood texture (band/hard noise) for extra nor around the edges.
Okay, here’s what I’m going for… a room full of treasure. I’ll keep pushing throughout the weekend to see just how much I can fill the room a lot more gold and silver on the way, coins, gems, more if the pace can be maintained.
Test renders are going considerably fast given the raytracing that’s going on, most likely because I’m not using much subsurfacing. It’s going so well so far I’m able to do most tests at 800x600 OSA 8. The ray tracer in 2.32 must be faster than ever. I’m now using the Intel compiled version, which apparently also helps speed things along.
RobertT
Wow Robert, I really like your “cloth study”
/JoOngle