Join Aaron F. Ross for an in-depth discussion in this video Balancing reflections with roughness, part of 3ds Max: Advanced Materials.
- [Instructor] One of the advantages of a Monte Carlo renderer like ART is the ability to interactively preview at production quality. We can make changes to our material and see a full production rendering in near real time. We'll use Active Shade to do that. Let's frame the sculpture in the perspective view so that we can basically crop out everything else, getting close on that, extreme close-up, maybe, and then enable safe frames, Shift + F, and it's cropped to the 0.666 aspect ratio we set earlier.
We'll need to set that up again for Active Shade. Go into the Render Setup dialogue, switch the target up here from Production Rendering Mode into Active Shade Mode, and then as soon as we do that, we see the aspect ratio change. Now set the renderer to ART and then the Output Size, set the Image Aspect to 0.666 and press Enter, then lock the aspect with the padlock, and I'll set the height to only 480 pixels for a fast update.
And then in the perspective view, just frame the shot, maybe dolly forward and back with the mouse wheel, and also we can use the field of view control here to zoom in more tightly, and if that object is selected with the Select Object tool we can also tumble around with Alt and middle mouse. All right, that is framed up pretty well as a test. We just need to go into the ART Renderer tab, and once again increase the target quality up to about 25 decibels, and with focus on this perspective pale, we can go ahead and do a rendering.
And now let's go into the Material Editor. We can close the Render Setup, go into the Material Editor, and make some changes, double click on our material in the view here, it's called sculpture physical. Let's set the base color down to black. Click on that, and let's make it nearly black, set the value to 0.001 and press Enter. And we can see now that we're getting some rim lighting, and that is because we have a very high Roughness value.
We can close the color selector. A roughness at a value of one gives us these very strong side highlights, almost as if it were a velvet object or maybe terra cotta or unfinished ceramic. Unlike with previous generations of computer graphics models, physically based rendering does not separate specular highlights from reflections. Here they're treated the same, and we can control the intensity of those highlights using the Roughness parameter.
Let's bring it down to its minimum of zero, press Enter, and now you can see we get very strong shiny specular highlights. The highlight we're seeing here in the middle is actually the white card, it's the flash that's behind the camera, and it has an area and it is always going to be visible in reflections in ART. You can experiment with different roughness values. Let's say a value of 0.2.
And now we're getting more of a metallic look even though we have not enabled the Metalness attribute or parameter yet. Maybe a value of 0.4, and now we're seeing the effect of having a sort of rough finish, and we're getting highlights almost everywhere and they're very soft. Increasing that up again to 0.6, and now the rim lighting or side lighting is taking over. Bringing the Roughness up to 0.8 approaches an ideal diffuse reflection, but because our diffuse color is nearly black, we are seeing these side lights.
Now that's coming from the BRDF settings we'll look at later. When we increase the Roughness back up to a value of one, we no longer have any specular highlights, and now we're just getting a diffuse reflection as if the surface were very porous and rough.
- Streamlining material editor workflow
- Managing XREFs and materials
- Laying out a scene for material testing
- Using the Physical Material
- Controlling highlights with Roughness
- Directing reflections and refractions
- Simulating translucency and scattering
- Building a shading network
- Combining and color correcting maps
- Baking maps such as ambient occlusion
- Procedural mapping with Substance
- Using relief maps: bump, normal, and displacement