Learn how to simulate polished and reflective surfaces.
- [Speaker] A highly-polished or metallic surface should have a low roughness and a high metalness in the Arnold standard surface material. Let's open up the material editor. I've got some nodes in the view already here. I'll just keep those there and navigate around to find an empty spot. Use the middle mouse button. Create a new Arnold standard surface shader. And that is found, once again, in materials. Arnold surface. Drag standard surface into the view.
Double click it to load its parameters, and rename it. We'll call it "vase Arnold standard." As I mentioned in previous movies, the objects in the scene are ex-refs, or external references, and if I ever need to unload those references, I'll want to keep a backup of the materials. So I'll go into the sample slots at the bottom here and drag from the output of the vase Arnold standard onto an empty slot and choose instance. Now I can assign the material.
Once again, click from the output of the material node onto the vase in the perspective view. And now, that's assigned. We're ready now to render an active shade. Click in the perspective view to give it focus, and click on active shade. And we've got an extreme close-up of the vase from the back so that we can get some really clear reflections. In the basic parameters, or diffuse section, we do want a white base color for a white metal, such as chrome. We also want the base color weight to be at its maximum of 1, so just increase that up.
Likewise, under specular reflections, we want white color, and we also do want a weight of 1, which is the default. But we won't see any metal effect until we increase the metalness parameter here. Click and drag and increase that, and as we approach 1, we get to a more or less mirror reflection. It's a little bit fuzzy in the reflection, and that's because the roughness here, under specular reflections, is set to 0.1.
If we bring the roughness down to its minimum of 0, we're creating a perfect first surface mirror, and that's a little bit unrealistic because that sort of thing doesn't exist in the real world very often, and usually, there is some glare on that surface. For highly-polished metal, I'd recommend a roughness of something like 0.05. In this case, I want it to be a little bit rougher than that. I'm going to set the roughness to 0.2. And in the active shade, we see we've got nice, blurry reflections now. We can stretch the highlights in various directions, using anisotropy.
I'll increase the anisotropy value amount up to its maximum of 1, and in the active shade, we can see that the highlights are stretched left to right. We can rotate that using the rotation value here. Set it to a value of 0.25. Now, we've got nice, longitudinal highlights, and maybe an anisotropy of 1 is too much. Maybe we'll bring it down to 0.6 or something. There's one last cool feature of metallic surfaces, which is reflective caustics. Let's look at the tablecloth at the bottom of the vase in the perspective view.
I'll go over there and use the middle mouse button to move the camera so that we can see the base of the vase and also the tablecloth. And in the basic parameters advanced, enable the switch that says, "Enable caustics." Now we see some light on the tablecloth. It's actually bouncing off the metallic surface, and we can orbit around with that vase still selected, alt and middle mouse to orbit around, and in the front, we'll see even more of a caustic effect.
And we can make that even more obvious by changing this to a gold material. Back in the base color, click on that color swatch. We'll set the hue to 0.1, The saturation at its maximum of 1, and the value at 0.75. Now, we've got a nice gold material here, and in our active shade render, we can see there's some gold tinting on the surface of the tablecloth, and that's the caustic effect.
Cool, so we can go a little bit wider now. We can maybe zoom back and examine scene. Alt and middle mouse to orbit, and middle mouse to move the camera. That's how to use roughness and metalness to achieve a highly-polished or metallic surface.
- Arnold rendering concepts
- Arnold lights such as quad, spot, and distant
- Modifying Arnold object properties
- Filtering light with the gobo filter modifier
- Image-based lighting with Skydome
- Daylight simulation with Physical Sky
- Arnold Standard Surface material parameters
- Diffuse, opacity, and bump mapping
- Rendering refractions with Transmission
- Building an Arnold shading network
- Test rendering with utility map
- Mesh subdivision and displacement at render time
- Atmospheric perspective with scene environment fog
- Rendering a spherical environment with VR Camera