In the previous article I did some talk about setting up materials, some things that we should avoid, and gave a couple of examples. Now, as I said there that I need a full post for glass, diamonds and related materials, I took the effort to go through different material setups with VRay and give tips and tricks for rendering refractive materials. So, let’s see how to render photorealistic glass and diamonds with VRay Materials!
I have been checking out some forums previously to see what people are using for glass rendering, and I was astonished that folks out there suggest, for example, turning off the Fresnel reflections for glass – which is not good. Glass type materials all have Fresnel reflections. Diamonds, water and basically all the liquids have it.
Testing Glass VRay Materials
So, I made 3 different materials and applied them to the same glass object. The first one has IOR of 1.5 and the second has IOR or 1.7. They both have Fresnel reflections turned on. Now, the third material has no Fresnel reflections, but I lowered the reflectiveness to 50% (gray color, RGB: 128/128/128). Let’s see how that looks like.
VRay Materials - glass material tests
VRay materials - settings for glass
Glass materials have IOR values around 1.5-1.7. Let’s say that’s a fair estimate. The first two glasses look OK, but the third one can’t really pass as a glass material. Good, it’s refracting and reflecting and all that, but it’s just not a glass (rather plastics). It looks interesting though.
It’s best to observe thing in nature (real world, that is). I was sitting in a cafe some days ago with my friend and she was talking about something (as usual). I was checking out how the glass that I had on the table reflects objects on steeper angles (Fresnel) and I was actually moving my finger around the glass to see how visible it became. Other than being accused that I’m not listening I found out that the glass really had nice Fresnel reflections. Luckily, I can multitask so I repeated what she said, so it was all good. OK, back to our VRay Materials.
Note that I also added a Fog color to the material, a light turquoise color with a certain multiplier. Regarding the fog multiplier, my value is set to 5. It greatly depends of the unit system you are using how this value effects the scene, and it’s also dependent of the object sizes, so I’m going to leave you experiment with it. If you are not getting the light turquoise colors on some parts of the glass, well, crank up the multiplier!
I’ll also add that the Max Depth parameter is important. If you want to speed up rendering lower those values to 10. I however like to keep those pretty high, so the light bounces around and produces a nice glassy effect.
For the sake of simplifying your life, I included a screenshot of the material settings of the middle glass object, so you can use those values to make your own VRay glass materials. Note that the top color pop-up is the color I used for the Fog Color. Click on the image for a bigger preview, and watch for the scroller when you do so on the right side – some pretty important settings are there in the lower part of the screenshot. Namely, the reflect on back side option, which needs to be turned on.
Advanced Glass Materials for VRay
Now that we are relatively happy with the VRay material we created, let’s kick up a notch.
All the refractive materials have dispersion effects. The dispersion of light is the effect when the light passes through a material and decomposes it’s spectrum by refracting different wave lengths with a slightly different IOR. This effect also produces rainbows, the zillion colors in a diamond and so on.
VRay 1.5 or older, does not have a dispersion effect incorporated within the material itself, so here, we are going to do a little trick. BTW, I hear the the new VRay 2.0 already has a built in dispersion control, and it works really good as I can see from the official demonstrations.
Dispersion trick material
Open a new material and choose it’s type to Vray Blend Material. Now, take your favorite glass material and copy it to the first 3 slots. Be careful not to make instances of the material, but copies, because we are going to modify those 3 separately. Note that the Base material is to be left empty.
Once you got that one, choose the fist color field right to the materials to red, green and blue. Use fully clear values as shown on the right screenshot. By this we are separating the red, green and blue photons and composing a material that will act differently for different wave lengths of light.
Once that is set up, go to each and every of the three materials and add a slightly higher IOR. The first (red) is 1.7, the second (green) is 1.75 and the third (green) is 1.8. Be careful to choose custom Fresnel reflections and set that value to 1.7, because reflection of light does not cause dispersion and rainbow effects.
Let’s see how that looks like!
Glass VRay material with light dispersion
Note that I turned on the caustics for this example, so it’s even more interesting to see how this trick works on dispersed refracted light. I also removed the chequer texture, so you can see the refraction and the “minimal rainbows” that it’s producing. The effect is much more profound in the next example I’m going to present you. The glass object walls are quite thin, so basically the dispersion is smaller than those in a diamond, for instance.
Rendering Diamonds With VRay
Another nice case when you need refractive materials setups is rendering of diamonds. Nice, shiny all the colors are present in them (for a white diamond, that is), no wonder that everyone likes them.
Diamonds have a very high index of refraction (2.417), which makes them break and bounce light internally much more than any glass or liquid type material. Basically that is what is making them so shiny and also adds “fire” to it, as the diamonds experts would say.
Diamonds rendered in VRay
The material I used here is basically same as the “rainbow glass” material, I just used IOR values for diamonds and turned off the fog color (set it’s color to full white). The IOR values for the refraction were gradually increased from (red) 2.417 to (green) 2.437 and (blue) 2.457.
This basically conludes the crash-course about rendering refractive VRay. Try to enjoy the experimentation with new materials, I know I did!
Great article and great info! I’m surprised nobody commented. You know your stuff sir!
Thank you!
this is a really good article! thanks for the rendering tips!
im a beginner with vray… always use mental ray… the materials are very similar.. this articles helps a lot… tks. Great job!
basically your opinion towards CG materials are intellectual, thanks for sharing sir. please keep us updated.
Hi , please can you offer any advice on making coloured glass in vray with sketchup? Im trying to make a stained glass window panel for my final project, (time is running out quickly!) at uni, so far i have managed to make a red glass pane by changing the fog and the transparency of refraction, however it only renders as red glass when in its own, if there is other geometry in the sketchup model is doesnt seem to work? Also I’ve tried to replicate what I’ve done to make yellow and orange glass too but it doesnt work.. what am I doing wrong?
Please email me with any tips I am at my wits end!!!!
Thank you in advance
Eleanor
If you used fog color, make sure the Fog Multiplier is set in regard to scene units used. That’s important if one work in 3DS Max, I really do not know for Sketchup.
Make sure the normals of the geometry are properly set.
Make sure the geometry’s transformation is reset – now this is really a wide subject, and if you do not know what is resetting the transforms of an object, please google it.
But, if you only need to make a stained glass window with constant refraction color, similar like ones used in churches, forget the fog color – simply apply a texture for the Refract color and set the fog color and parameters back to default. In this case you do not need fog and that parameter group.
This is all I can think of this moment, sorry for not being more familiar with Sketchup and how it works with VRay.
Hope this helps!
Robeto recently posted..Vray Materials – Glass and Diamonds
I am a beginner with video editing. I hope to learn this in the near future.
saraden recently posted..Is it Okay to Have 2 or more Antivirus in your Computer?
Hey Thanks for tutorials
But can you tell me about lightening & rendering setup over this material
that could be very useful for me….
Regards
Rajesh
Thanks for the comment Rajesh!
Actually, I’m planning to do a detailed render settings post, which is related to your question. This just would not tend to fit in the comment section, so stay tuned! Will see to post that in the following weeks, as I’m quite busy at the moment.
Roberto recently posted..Vray Materials – Glass and Diamonds
I was so amazed that kind such thing exist.I’m glad you posted it in order to have some view of the investors.An idea on how to have it.
Angelo recently posted..How to win the lottery
These diamonds are very brilliant ones! Are these diamonds real? I am pretty sure that these are so expensive.
Manthie recently posted..autorent
I don’t think that is real. It is edited and placed some background. It lures people to digital imaging.
Meepo recently posted..Pharmacy Technician
Thanks! Good to know that I mostly mastered the VRay visualization subject
your glass looks incredible, however the diamonds are a tad bit dark. lighten them up in the render settings and i think you should be good to go. I really like the left goblet though, the glass looks very realistic to me. congrats on the work well done.
alexa008 recently posted..Zebra Rug
Thanks Alexa! Did a lot of work on those VRay materials. Had a nice reference for the glass, but I did not have diamonds around me at that moment.
However, I’m with you about lightening up the diamonds. Should help.
Thanks for your input!
I was looking for this kind of information for quite a while now. Glad to be around your post, it’s really helpful and easy to learn. Keep up the good work.
Laura recently posted..Forex
How would you go making a prism material with vray? Im trying, unsuccessfully, to add the prism effect to a window render for a proyect.
I’m not sure what do you mean by a prism material? Glass already can be a material for prism, if you assign it to a prism – which is a geometrical form.
By prism effect, I can figure that you are talking about a dispersion effect?
If so, simply use the VRay material and set up glass as explained in this article. If you are using VRay 2.xx then you just need to fire up the ABBE parameter which actually does the color dispersion effect without the trick I explain in this article. There is a parameter controlling the dispersion value – the lower this value, the more colors are going to be separated. So, don’t cranck it up too high – it will kill the effect.
Note that the visibility of this effect if greatly affected by how light shines to the window, the thickness, etc. Try shooting a ray of light onto the window and see how it works first, like a sort of test.
Hi Roberto, very nice tutorials and shaders, specially the glass one, very useful to me. Let me ask you something, i usualy need to create a glass material to a table, or to a shelve (check the image links i send you below, please), and I always have great difficulty to set the shader. what i use to do is use two diferent shaders, one for the top/bottom part of the shelve, and other to the edges (the side, the darker part of the glass). Do you have a specific shader fot this kind of glass? i tried to use the shader of this tutorial, but depending the position of the camera, the top got all green (fog color) and no reflection or transparency.
Thanks in advance,
Juliano
the reference image links:
http://www.qualityenclosures.com/_assets/img/products/glass-and-mirror/glass-shelf-3.jpg
http://www.glassshelf.co.uk/images/glass-shelf-with-supports.jpg
Juliano, I just checked the reference images, and they look pretty good to me. The reflections get stronger as the camera angle is steeper towards the surfaces, and as reflections get weaker refraction kicks in.
This is how it works in nature, and this is what I see on those images.
As for your settings, I’m sure that the tutorial explained here should work, however, I might be that one of us forgot to do/explain an important thing. So, I’ll shoot you an email so you can send me the file to check it out.
There should be only one material. No side and top stuff. Just a single properly set glass material.
When we learn what was the problem, I’ll post an answer here, so hopefuly others can also learn from the example.
After checking out the glass material setup, we needed to adjust the IOR to 1.6, both reflect and refract.
Next, both reflect and refract colors are to be set close to pure white: RGB 253/253/253 is OK, or something close to those values +- 10.
Finally, we fired up the “Reflect on Back Side” in the “Options” rollout of the material settings and voila! Don’t forget this one – it is important!
So, with these 3 adjustments, Juliano’s glass material got a whole lot better. Got saved in the material library after that too.
[...] Basically that is all I wanted to introduce to you in this article about VRay materials. The only significant property that I did not elaborate about are refractive materials (glass, water, diamonds…) because it deserves a separate post/web page – the subject matter is a bit more complex, so I’ll need more space to wave around. However, the material is under preparation and will be available soon. Correction, I added the post! Click the link to check out the Glass and Refractive VRay Materials! [...]
Awsome work dear..!!!
vray black and white room render settings
i think you greate