First Render

[ZYX]

Hi, I'm ZYX and I'm new to Luxrender. I wanted to post the picture of my very first render with luxrender . BTW, luxrender is a very cool program, it's a lot better than I expected. And I know that there is a lot of first render pictures already, hope I don't bother, .

[ZYX]

btw, this is my model but I didn't model this specifically to render it with luxrender, so I don'treally know if it counts

[paco]

Looks good to me. It's a lot better than my first render

[ZYX]

Thanks. I'm thinking in cleaning the render a bit and maybe posting it into the gallery. What do you say? does it need more work or is the scene good as it is?

[B.Y.O.B.]

Thanks. I'm thinking in cleaning the render a bit and maybe posting it into the gallery.

I think that's a good idea.

[Skywise]

They seem too dark to me. And the dispersion seems exaggerated.

Mine always come out bright and the dispersion is hardly noticeable. But, I stick to 'real' settings.

Another question, is your model accurate? The 'brilliant cut' shape is very precise and is designed to make a bright diamond. Before the advent of proper cuts, diamonds were dark, sometimes almost black. Don't know how much you know, but I've spent many an hour studying pictures of real diamonds and reading about the history of various cuts in search of making the most realistic diamonds I can. The articles on Wikipedia are a pretty good start.

http://en.wikipedia.org/wiki/Brilliant_cut
http://en.wikipedia.org/wiki/Diamond_cut

For pictures, just use Google image search for "diamond".

My attached image was inspired by yours. It was rendered to 5kS/p using Lux v0.8 and Blender 2.6 and took about 20-1/2 hours on my Core2 Quad 3.0Ghz (Q9650).

model: 3DLapidary - http://www.3dlapidary.com/ - standard round brilliant
hdri: HDRLabs - http://www.hdrlabs.com/sibl/archive.html - "Charles River Esplanade"

Hope my input helps.

Brian

[strahlentherapeut]

you are right skywise,

the diamonds ( brilliants) from xyz have no correct cut. They have no "edge"? ( in my language german - Rundiste). And there are too many dispersive refraction. They seems like fake ( polished, cut window glass).
A photographer would take care to avoid such d-refraction . Diamonds have a special reflection, like an internal emitter The second pic of diamonds are nice too. But they are too bright and too blue. But both render are nice made.
The caustics of the first d-pic are very good.

st

[ZYX]

Actually, they do have an edge. Although, I think it isn't very accurate. Also, I think the dark is because there is no environment lightning, only area lights; I'll add an environment in the next img.
For the dispersion and the IOR I used data in wikipedia, but I guess it's not the best source .

[Skywise]

ST, you could be right about the 'too bright', but it seems mine are always that way. Also, all the well lit pics of diamonds I find show them to bright and white. The only time I get a dark diamond is when I don't have any light on it. As for the blue, that's probably just due to the environment map - blue sky.

I'll experiment some more....

Brian

[Skywise]

OK, I did a comparison on my scene with various combinations of Hemi/HDRI, Sun, and Sun/Sky lamps.

My original scene has the HDRI along with a Sun/Sky lamp, and hence tends to be bluish. The lesson here seems to be that the best image is obtained with the HDRI and a Sun lamp, but make sure to turn off the sky portion of the Sun lamp.

Settings - Light groups set for Sun/Sky = 0.25 and HDRI = 10,000. Did not have dispersion turned on so the scene would converge quickly. (30 minutes each)

As a curiosity, having only an HDRI and a Sky washes out to pretty much nothing.

Note how the white table surface shifts color/white balance depending on illumination source.

Also note that the Sun only image shows 'black' diamonds. The brightness of the gem is dependent on reflecting the environment around it. Even the Sun/Sky combination looks dull. "Watery" comes to mind.

Again, to me at least, the clear winner is the top right image.

Brian