In this tutorial, you learn about the new Physical Material that made its debut in 3ds Max 2017. Open the file named Physical Material.max that you downloaded for this tutorial. A download link is available in the description section of this movie. The scene is simple with only a few objects, lights and a single camera. It is set to use the new ART Renderer, and to make testing easier, the rendering target is set to ActiveShade mode. In fact, for the purposes of this tutorial, you will find it very handy to use ActiveShade in a viewport. The rendering is progressive and keeps getting better until you stop it or make a change to the scene. If you'd like to learn how to set ActiveShade in a viewport, watch the tutorial named "Setting ActiveShade in a Viewport" available on this channel. Open the Material Editor and arrange it so you can see it next to the rendering viewport. Create a new Physical Material by dragging it into the working area. Double-click it to view its parameters. Apply it to the shader ball, the ActiveShade viewport reacts accordingly. The first thing to notice is that you have a number of Preset templates to choose from. These are easy to access and can get you a head start in your project. Test out a few to get a feel for them. What these templates are doing is simply filling the appropriate parameter values of the material. Once you understand how these parameters work, you'll be able to create any real-world material you can think of. Delete all the nodes that got created and add a new Physical Material and apply it to the shader ball again. Take a look at the properties one more time. There are two modes you can use to display the Basic Parameters: Standard and Advanced. In Standard mode, the material's Base color and Reflections are combined into one section. In Advanced mode, they are split into two distinctive sections. Advanced mode also has an Advanced Reflectance Parameters section so that you can customize reflection behavior. However, you are strongly encouraged to rely on Fresnel IOR values as they work best with the Physical Material. The base color is the closest you have to a Diffuse color, essentially the base color of the material. Reflection color is white by default but you can see its effect by using a different color. To better appreciate the various control values, you will experiment by creating a few varied material types. Start with glass; this is always an interesting and historically difficult material to achieve. Reset the material values or simply create a new one if you need to. The thing about glass, or clear glass at least, is that it actually has no base color. It's the reflection and refraction values that make it appear the way it does. Bring down the Base Color value to 0, the model turns black. Leave the Reflection to 1 as transparent glass is usually quite reflective, and crank up the Transparency all the way to 1. That's a very quick and easy way to create glass. You can see the refractive properties of the material as the tile lines distort underneath the glass. The distortion is a direct effect of the Fresnel IOR value. A value of 1 creates no distortion. I like to keep glass IOR values between 1.2 and 1.7 IOR but you can experiment more with that. I'll set it to about 1.65 for now. You may have noticed a Thin-walled option. This is meant for single-faced window panes and provides no refraction or volume data. Do not use this option if you're not dealing with single-faced elements. Tinted glass is even more fun. Change the Transparency color to a green color that you like. It's nice but seems somehow more opaque due to the darker color. Note the Transparency Depth value; this controls the density of the glass. Set it to 1cm, and notice the effects in the render window. Note how the glass is more transparent where it's thinner and more opaque where it's thicker. The higher the Depth value and the less dense the glass is, as it allows more light to travel through. Try other values to see their effect. As a reference, the tiles on the floor (not the checkered pattern but the tiles themselves) are 10cmx10cm. You can also add Sub-Surface Scattering which is essentially for translucent materials, but which can also have a nice effect on glass. Here's what you have to remember: Some of these values work in tandem so that the total value is no more than 100%. If Transparency is set to 1 (or 100%) then Sub-Surface Scattering is disabled. Test it out: set it to a bright red color with a weight of 1. Note that it has absolutely no effect on the scene. Bring down the Transparency weight to about 0.85 and you'll notice that light travelling through the glass has a red tint to it. SSS also has its own Depth value to determine how deep light scatters under the surface. Let's try a different type of material, something metallic: Create a new Physical Material, and apply it to the shader ball. Double-click it to edit its properties and set it to Advanced mode. Like glass, metal relies very little on a base color and far more on reflections, especially with glossy metals like chrome. However, bringing the base color down to 0 with reflections cranked up high gives you a very dark material. To make it more reflective to simulate chrome, you need to significantly increase the IOR value. IOR values for metal start at around 4 and move all the way up to 50 for chromes and other slick-looking metals. However, even setting the IOR to 50 still shows large areas of black reflections. That's because of how the scene is set up; there is not much to reflect other than the floor. Instead of building more geometry, you can use an HDRI background to reflect in the metal. It will also help with the lighting of the scene. You can google for HDR panoramas to find one that you like. I found one that works well on the USC Institute for Creative Technologies web site (http://gl.ict.usc.edu/Data/HighResProbes/) In fact, they have several, I used the Grace Cathedral one in .hdr format. Once you've downloaded it, simply go to the Environment dialog, and load the HDR image as a background. You will undoubtedly need to change the camera's EV value to compensate for the increase in lighting. With the Cathedral background, I used an EV value of 8. With this, the material looks much more like Chrome. To turn this chrome material into a rougher metal such as Aluminum, you can start by editing the Roughness value to blur the reflections You can also make the metal darker by darkening the reflection color. This is a good base for aluminum or a stainless steel material. Note that with very high IOR values, the base color weight has very little effect on the material. Decrease the IOR value to about 6, you lose the metal look. You can compensate by setting the Metalness value to 1, to get the metal look back, as it was with very high IOR values When Metalness is set to 0, light enters the model and reflections are based on the surface and sub-surface properties of the object. When Metalness is set to 1, reflections are based on the surface alone and anything underneath is regarded as opaque. Alternatively, you can use a map to alter the roughness channel. You may need to edit the map for brightness, contrast and tiling to get the desired effect, in this case old, aged metal. Let's try a wood material, create a new Physical Material and assign it to the model. In the Base Color channel, use a wooden texture bitmap, and make sure you are in Advanced mode. Right off the bat, you have a very nice reflective wood material. For wood, I like to use value between 1.5 and 2.2 You can edit the roughness depending how varnished you want the wood to be. Here's the fun part, you can add a Coating layer on top of the material you've defined. For wood, it's like adding a topcoat layer of varnish. Open the Coating Parameters rollout, and choose a dark beige, brownish color. Note that the coating layer has its own IOR value. Set that value to about 2.5, and the weight to 0.5, you should see your wood texture darken in the viewport. Adjust the Affect Underlying Color value to see the results. This is like polishing and staining and old parquet floor to give it a new life. Let's do one more material to simulate polished stone or ceramic tiles. Create a new Physical Material and apply it as you have learned to do. Add a Tiles map to the Base Color channel, and set the tiling to 2x2. First off notice the fact that the material is reflecting both on the tile and in the grout. To prevent this from happening, duplicate the map using Shift+Move, and then apply the duplicate to the Reflectivity Map channel. Double-click the new map, and in Advanced Controls, adjust its colors. Set the grout color very dark to prevent any reflections there. Set the Texture color to a very bright grey but not completely white. I like to prevent using extremes when using physical materials. You can also connect this map to the bump channel for more effect. Now go back to adjusting the material's parameters. For polished stone or ceramics, an IOR value between 1.6 and 2.8 should do. You may elect to adjust other values as well, such as Roughness. For the Tile color, you can go back to editing the color value in the Base Color channel or use a map. In addition to what you have learned so far, there is one more parameter you haven't experimented with, the Emission parameter. This parameter makes the material self-illuminated; and actually contributes to scene lighting. The material itself becomes a light source. Set the weight to 1 to see the effect of white illumination. You can adjust the emission color value, and the color temperature for more varied results, as well as the Luminance value to control the intensity of the generated light. Now that you have experimented with different material types, it is up to you to come up with your own. You can rely on what you have learned in this tutorial and also by analyzing the parameters of the samples found in the Presets list. I hope you have enjoyed this tutorial and will be back with you very soon.
