View Full Version : Diamond or polylight

07-13-2011, 02:28 AM
I have a question. I have to do a rotating cup with three diamonds in the ear cup. Background is black and only one spotlight above. The main question is - why the diamonds don't sparkle?


Support question: how (if this a way) convert diamonds to a polylights?

Support question 2: how to setup of diamond to get high level of sparkle when they are closest to camera? Probably by transparency/gradient/Distance to camera in texture Editor tab, but i don't know settings.

Support question 3: it is possible to get an effect a... hmm when the spotlight is above of cup I see only a white circle on the let say, ground. And it is good. But I want to get an effect of a slightly smoky space in which the beam can be seen? I hope You understand me ;))

07-13-2011, 04:09 AM
Add some reflection to your scene. Or put a reflection map in the reflection surface properties. Or render in with a nice HDRI in the environment.

07-14-2011, 01:43 AM
There is reflection. In environment tab is ray tracking+spherical map and in backdrop tab is image world map. :(

07-14-2011, 08:29 AM
I'm thinking it has a lot to do with transparency/refraction and lack of bright objects in the scene. Try some HDR environments maps and turn on transparency and put the IOR to 2.4 (or whatever starts to look right). It looks as if the diamond objects are opaque, reflection alone cannot do the job. You could also do some dispersion (refraction and specular/reflection) to help but you will have to setup a node based material for this.

07-14-2011, 08:52 AM
Also, If you ever go to a jewelry store, look at the lighting. They usually have a lots and lots of small lights around the cases. They probably do that so the shiny, reflective, refractive surfaces have lots of things to reflect/refract so they sparkle more.

One big light won't do it.


07-14-2011, 10:16 AM
Make the 'back' of the Diamonds have a metal finish, so there's more surfaces which will reflect highlights.

Also go into the diamond material settings and add some refraction and reflection dispersion to it. You will need to have some reflection blur/refraction blur in the settings, even if it's only a tiny a value, and use a shader which supports it. Either use the built in Reflection/Refraction node shaders, or use Dielectric, which is simpler. Also make sure you give the Diamond a high enough IOR/refraction index (Diamond has an IOR of 2.417) So that the rays are correctly dispersed round the material. That should make your reflections sparkle more!

Also to get the coloured highlights, make sure you add something very bright and white (luminosity of at least 300%) or all you will get is some Specular highlights, which don't do colour dispersion effects.

07-14-2011, 11:24 AM
There is reflection. In environment tab is ray tracking+spherical map and in backdrop tab is image world map. :(

Ray tracing + spherical map doesn't reflect the backdrop, you need ray tracing + backdrop.

07-20-2011, 02:31 PM
btw, might be of use...

07-22-2011, 03:10 AM
I would use HDRI for environment/reflectionmap. Render a test and save in some HDR format. Make a composition in AE or some other application of choise. Duplicate the rendered layer and press the contrast way up, so you only get the brightest pixels (that correspond to the highlights) and blur that layer a bit and set the blendmode to something like screen.

Quick and easy way to get a Bloom like effect.