FREE Vray Tutorial - Render glass and liquid [1] aversis.be/tutorials/vray/vray-20-glass-liquid-01.htm
Please don't translate or copy these tutorials elsewhere. I don't like the tutorials to float around in 10 different versions and places on the net. Feel free to link to this page of course! (see also Terms of Use)
Before you start This tutorial is all about rendering glass and liquid in V-ray. It's quite basic, but even for experienced users there might be some useful tips and tricks! V-ray version 3.0 was used to create this tutorial. You will probably be able to follow along even with older versions, but some screenshots may vary, or some settings may changed place or will have a slightly different effect on image quality. The included files are all 3D Studio Max 2013. These will open fine in newer max version, but you will not be able to open them in older ones! You are allowed to use everything you find in the sample files for your own projects, but you are not allowed to use the textures, models or any part of the file to resell or redistribute.
First learn 3D Studio Max, then start with Vray. It is an extension to 3DS Max, not a replacement! For example things like the material editor, creating and manipulating objects, modifiers etc should all be familiar before trying to learn Vray.
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Startup scene Please download the startup 3DsMax file here: glass-liquid-startup.rar Note that this is a 3DsMax2013 file, so you need at least that version to open it. Please don't email me for older versions... The scene features a typical studio setup: White photo-studio groundplane/background A few big rectangular lights We also use the gamma 2.2 setup, please read that tutorial first if you don't know what I'm talking about. If you open the startup scene and accept all the warning dialogs, you should be fine. GI is enabled, and there's a a black environment override color for reflection/refraction.
Wineglass Currently both groundplane and wineglass have the same white, non reflective material. Hit render and you should get the image below. As you can see, the main lighting is coming from the right and from the top. On the left there is a third light which is tinted slightly blue.
Glass material In the material editor, copy the floor material to a new slot, rename it 'glass' and apply it to the wineglass object.
Glass material - diffuse and refraction color First we will change the diffuse color to pure black, and the refraction color to pure white. This is the best way to create any kind of glass material. Effectively you are disabling the diffuse color (pure black) and then by setting refraction to pure white you make is 100% transparent. If you would like to know more about vray material creation, here's a basic V-ray material tutorial. So with the newly created glass material applied to the wineglass, hit render to check out the result so far. It doesn't really look like glass, but it is indeed very transparent.
Glass material - reflections We also need to make the glass material reflective , so simply change the reflection color to a light grey, and make sure you have Fresnel reflections also checked. Now when you render, it's starting to look more like real glass.
Glass IOR Change the IOR in refraction parameters to 1,45. Each material has a typical IOR value, and for glass 1,45 is a good starting point. This will also dim the reflections a little bit, since the reflection IOR is linked to the refraction IOR by default. The lower the IOR, the less refraction is going on, and the less reflective the object will become.
Glass color - Fog Instead of using a tinted refraction color, we will be using the 'fog' parameter to color the glass. Change the white fog color to something like in the screenshot. I found that medium grey values work best, with a slight tint of the color you want in it. I chose a blueish tint, but don't overdo it since the goal here is to create normal transparent glass.
When you render, the result looks a bit strange. The glass suddenly becomes very dark.
Glass color - fog multiplier To change the effect of the fog color, lower the fog multiplier to 0,1 and render again.
As you see, the glass becomes more transparent, but the regions where a lot of refraction is going on, stay dark (thicker parts of the wineglass). This looks a lot more like real glass, for example take a look at this picture. Of course, the look of the glass will depend heavily on the environment it is photographed in!
Reduce the multiplier even further to 0,02. This will make the material even more transparent, as expected. The thinner parts look more real, but the thicker parts now also became a bit too transparant.
Glass color - fog bias To get the best of both worlds, you can use the fog bias. Change it to -0,3 and do a test render. As you can see, the thinner parts look almost the same as before, while the thicker parts become a lot darker.
Max depth for reflection and refraction Another thing we will be changing, is the max depth setting for both reflections and refractions. To speed up rendering, this is set to 5 by default. So vray will by default stop tracing rays when they effectively passed 5 surfaces. For example in our scene, when you look through the upper part of the wineglass, you pass 4 surfaces (the glass has thickness, so there are 2 surfaces on each side of the glass).
It's the same for reflections, when a reflection is reflected, and that one is again reflected and so on, this can go on forever. It's like when you're in between 2 mirrors facing each other, your reflection will be reflected in infinity. Click here for an example. So to speed up calculations, you can control the depth of reflections and refractions that will be calculated by Vray. Usually 5 is enough, but since we are rendering glass specifically, increase the depth to 12 for both reflections and refractions. Note that the difference is subtle...
Reflect on backside In the options rollout of the glass material, turn on the 'reflect on backside' option. You will see that now also the inside of the glass surfaces reflect the light sources (looks like double reflections in the upper part of the glass).
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FREE Vray Tutorial - Render glass and liquid [2] aversis.be/tutorials/vray/vray-20-glass-liquid-02.htm
Please don't translate or copy these tutorials elsewhere. I don't like the tutorials to float around in 10 different versions and places on the net. Feel free to link to this page of course! (see also Terms of Use)
Before you start If you discovered this Vray tutorial page through a direct link or search engine, please note that you're on page 2 of the tutorial! Please complete page 1 first if you haven't done so.
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Water object Unhide the 'water outside' object and do a test render.
This 'water' object currently has a white opaque material applied.
Water material Copy the glass material to a new slot and rename it 'water'. Apply the water material to the water object, and hit render. As you can see, the water doesn't look very tasty...
Water material First, change the IOR to 1,33. This the correct IOR value for water. Then make the fog color a lot brighter, as in the second screenshot. We don't want to darken the thick parts as with the glass material, so set the fog bias to 0 again.
Now render again, this looks more like it!
How to model the Water object!? In order to render realistic liquid inside a glass, there is a small trick you need to take care of... First of all, because of adhesive forces, the water surface will be curved where it touches the glass. So if you want realistic results, you have to model this effect. If you zoom in on the edges of the water object, you will see it has a slight curve, it is
not simply a straight cap! Then there is an even more important detail when modeling the water object. The screenshot below shows 3 ways to model it. The first one is to model the water surface smaller than the glass inside surface. As you can see in the render below it, this doesn't give the desired effect. Take a look at a real glass filled with water, this is not how it should look like! The third image shows the water object modeled exactly against the inside glass surface. This means that the water object and glass object intersect each other, and as you can see in the rendered example, this results in strange looking effects. The middle image is how it should be. You make sure that the upward curve touches the inside of the glass, and then you model the rest of the water sides LARGER than the inside surface of the glass. In this case it is just 0.1mm larger, which is already enough. The rendering below shows that this is the way it should be modeled.
So keep these 2 tips in mind when modeling your liquids inside a glass.
Red wine material Copy the water material to a new slot and rename it 'red wine'.
To better see the materials in the editor, click the background button for each material:
Change the fog color to a light, not too saturated red color.
Hit render and behold, the water is turned into red wine! (More like a cheap rosé though)
Red wine is darker Change the fog color to 0.05, to make the wine darker. This isn't perfect yet, but you get the point. If you want, play around with fog color and fog multiplier to get various effects. You can find this scene here, in case you got lost it's a good thing to carry on from here.
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FREE Vray Tutorial - Render glass and liquid [3] aversis.be/tutorials/vray/vray-20-glass-liquid-03.htm
Please don't translate or copy these tutorials elsewhere. I don't like the tutorials to float around in 10 different versions and places on the net. Feel free to link to this page of course! (see also Terms of Use)
Before you start If you discovered this Vray tutorial page through a direct link or search engine, please note that you're on page 3 of the tutorial! Please complete page 1 and page 2 first if you haven't done so.
Page 1 - Page 2 - Page 3
Empty the glass Select and hide the 'water' object. Hit render and you should get an image of an empty glass again.
Dispersion Dispersion is a subtle effect seen sometimes in pictures of glass, where the glass will color like a rainbow in some areas. I will not go into detail why this effect occurs, we have wikipedia for that: http://en.wikipedia.org/wiki/Dispersion_(optics) Since V-ray 2.0, rendering dispersion is as easy as ticking a checkbox! So that's what we'll do, just enable the dispersion checkbox and hit render. Note that the effect is very subtle, and render times increase a lot (10s vs 25s).
When zoomed in, the effect becomes more visible. Even though the effect is subtle, it will add to the realism of your image. Especially if you're doing close ups in highres, dispersion can be very beatifull.
Dispersion - abbe Dispersion only has one setting: abbe. Lower it to 10 and render. You'll see the effect becomes more visible now, but a bit too much.
Final render Set abbe to 35, to get something in between. You can find this end scene here.
Play around with the scene Here's an extra scene with a few copies of the glass and wine. We changed the materials slightly to create 3 types of wine. Added a different camera angle, used some vray DOF to focus on the front glass and then added a little bit of contrast and a vignette in photoshop. Also the render settings have been altered for higher quality. Note that this image rendered 11 minutes, while the previous one was only 30 seconds. So depending on your machine this scene can take a while to render. You can download this final max scene here. Or download the PSD file with layers here.
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