In this tutorial we will go through the process of creating realistic wet materials. Although the tutorial is written for max and vray users, the same workflow can be adapted to any software you may use.

1) Analyzing the reference
In order to re-create any type of material the first and most important thing is to look at real photos of what you are trying to replicate in your rendering, and really understand what is happening there.

For example, take a close look at the photo bellow.

Not only the asphalt is quite reflective because of the layer of water on it, but also the glossiness/specular varies a lot across the image. In areas where the layer of water is thicker the reflections are a lot sharper and the bump of the asphalt is less present. In other areas, where the asphalt is dryer, the reflections become glossy and they are also distorted by the bumps on the street.

2) Replicating the effect with 3ds max tools and vray.
To sum it up, in order to create a wet asphalt shader we need a diffuse map, a bump map, a reflection map and most importantly a map for the glossiness chanel.
Open the “wet materials scene” that you find in this zip file.

Although all the maps are already there, they are not activated yet; we will activate them one by one to better understand how each of them affects the overall look.

a)    The reflection map

For the reflection, I have used a falloff with 2 maps (basically a darker version and a lighter version), for more control. Besides the brightness both maps are identical.
The areas close to the edges (where I want the layer of water to be thicker) are whiter and more uniform, while other areas are darker and noisy.

Activate the reflection map by clicking the checkbox next to it in the maps rollout.
If you hit render, at this stage you will end up with something like this:

b)    The bump map
If you activate the map and hit render you will notice that the reflections are distorted in the areas where the map has noise applied. Again, in other areas where there is more water, you need to paint it with neutral gray, since there is no bumpiness.

c)    The reflection glossiness map
This one makes all the difference. Before activating it, the reflection, although distorted by the bump map in some place is still very sharp an unnatural. As we have noticed from the reference image at the beginning of the tutorial, this should vary across the image, depending again by the thickness of the layer of water. White causes the reflection to be sharp (equivalent to “1” from the glossiness parameter), while darker values make the reflection much more glossy.
If you hit a render after having activated it, you will end up with something like the following:

d)    The diffuse map.
Although not really important for the purpose of this tutorial, it has quite an impact on the realism of the image, so activate that as well and hit a final render.

If there is something you don’t understand or if you have any kind of questions, don’t hesitate to ask.

In this example we will try to “paint” a pathway on a hilly landscape.
Start with a 30mx30m plane object and add around 100 length segments and around 100 width segments. Covert it to editable poly and drag vertices on the z axis, with soft selection active, until you get something similar to the following:

Assign a blend material to the geometry. In the first material slot (inside the blend material) apply a grass texture, and in the second slot apply a gravel/sand map (this will be the texture for the pathway). Don’t forget to add a planar uvw map to the mesh adjust the tiling until you are happy with the result.

In the “mask” slot, choose “vertex color”, like in the screen capture bellow.

Now add a vertex paint modifier to the geometry and using the brush tool, paint a black pathway wherever you want. You can easily adjust the size of the brush to anything you want.

Believe it or not, that’s all. If you hit render you should end up with something similar to the following image.

As I said at the beginning of the tutorial, there are several situations where you can use the vertex paint modifier: you can use it to add more variety to large surfaces covered with grass, concrete walls, or even create tire tracks.
*If you use vray, than use the “vray blend material” instead of the “standard” blend.

This is a short tutorial that explains how to create a stone material in 3ds max without using any textures, only procedural maps. The tutorial has been written for vray, but the same concept can be applied to mental ray as well.

Create a chamfer box and apply a vray material to it. Click the bump slot of the material (in the maps rollout) and choose “Perlin Marble”.

In both slots of the perlin marble parameters choose smoke, and adjust the settings like in the following image:

Now apply a vraydisplacement modifier to the object, choose 3D mapping, set the amount to 5-6cm and drag the previously created perlin marble map on to the texmap slot.

It is important to set the displacement method to 3d mapping, since 2d mapping doesn’t work with procedural maps.

At this point we only need to add something in the diffuse channel. In this case I have added a smoke map with 2 different noise maps for both slots, like in the screen captures bellow:

That’s it.

Some conclusions:
The parameters of each map, don’t have to be exactly the ones that I have used in this tutorial. The important thing is to diversify them as much as possible, so there won’t be any visible repeated patterns in the rendering. That is the reason we have used mixed maps in the first place.
The main disadvantage of using this method is that you need 3d mapping for vray displacement, which implies longer rendering times.

In an effort to keep this tutorial as simple as it can be, I have touched only the diffuse and the bump channels of the material, but if you feel like experimenting more, don’t be afraid to play with other channels as well (especially reflection). You can obtain several materials like various types of stones, concrete, rough terrain, mud etc.
You can also combine 2d raster maps with procedural ones… sky’s the limit.
Here is the 3d max scene that I used for this tutorial (grass maps not included).

If you try this method and obtain some results that you like, I would be happy to see them; feel free to contact me at cgdigest (at) gmail (dot) com

If you went through that tutorial, you’ve most probably noticed that the rendering times, when you activate blurred reflections and refractions are considerably high.
However, if you are not rendering an animation and the final product is a still rendering, there is another way around it; this is what I’m trying to explain in this tutorial.

The first thing that you need to do is to start with material settings suitable for clear glass, with no blurred reflections of refractions. Duplicate the material, rename it, and make it a vray material wrapper, with the base material being the clear glass.
Change the alpha contribution parameter to “-1” and keep the rest untouched.

Now select the polygons like in the image bellow and assign the new material only to this selection.

In case you are wondering why you didn’t assign the new material, the answer is simple; we will going to tweak this in post processing in order to add blur reflection and reflection, but we need to keep the edges sharp.

Render a high resolution rendering, and save the result as a tiff with alpha channel.

Open the rendering in photoshop.
Click on “select”, “load selection”, “alpha 1”, than invert the selection.
At this point you have the material selected and you can start tweaking it.
In order to have blurred reflections and refractions, click on filters, blur, and choose Gaussian blur.
One of the advantages of using this method is that you can adjust the amount of blur that you need in your image dynamically, without having to render the scene again.
Also, you have more control on the color simply by adjusting the color balance.
Bellow are 3 examples that I managed to do in a few seconds using this method (if I had to do it directly in 3d, I would have had to render each one separately):

As you can see these images are already similar to the renderings done directly in 3d.
You can take them even further by using filters like glass (tiny lens, canvas or blocks) or any other filter that fit your needs..

As I said previously, this method of creating frosted glass with photoshop has a lot of advantages; however it has some disadvantages as well. Besides not working for animations, you can not control the amount of blur for reflections and refractions separately.

Depending on what are your requirements you can choose either of the methods shown above.

If there is something you don’t understand, feel free to ask!