Learn how to apply Physical Sky illumination and background.
- [Instructor] The Max 2A Arnold plug-in does support the 3DS max sun positioner and physical sky for simulating daylight. Arnold also provides a native physical sky environment that I actually prefer because its colors are more neutral. Let's create an Arnold physical sky environment, let's check in on our exposure under rendering, exposure control. I have it set to a realistic value for a mid-afternoon in bright daylight.
That exposure value is 13. With the camera exposure set to a plausible real-world value, I can adjust the intensity of the physical sky to achieve a realistic daylight effect. Let's add the environment map. In a common parameters, click the environment map button. In the material map browser, we want to open up the Arnold section. So close the general section for the maps. Open up Arnold. Environment. And double-click physical sky.
And now that's been applied, let's see what it looks like. Do an active shade render of the physical camera. We get a nearly black screen, so let's edit the parameters of the physical sky. Open up the material editor. And drag the environment map from the environment and effects dialogue over into the slate material editor. Choose instance. Double-click the node to load its parameters and rename it. We'll call it physical sky Arnold.
Let's get our active shade window visible. Select that. And increase the intensity of the physical sky. Set that to a value of 200. And that looks like about the right exposure, but of course you could adjust this up or down. All right, 200 looks good. Most importantly, the coordinate system for the physical sky needs to be set. We have X, Y and Z axis. And depending upon the version of 3DS Max you're running, these may not be set up to the correct defaults.
We want the X axis to be one in the X field here, in the upper left corner. So set that to one. The middle one here, under X axis, set to zero. Then for the Y axis below it, it's set to the default currently on my system. Zero, zero and one. And finally the Z axis, we want that to be in the first field a value of zero. In the second field a value of one.
And the third field a value of zero. Once again, X axis should read one, zero, zero. Y axis, zero, zero, one. And Z axis zero, one, zero. And our sun is showing up in the active shade rendering. We can control the position of the sun in the sky using the azimuth and elevation. The elevation I'll leave at 45 degrees. Let's drag the spinner for the azimuth. I want that to be around 215, so I'll type that in.
Type in 215 and press enter. And now the sun is positioned to roughly align with the image-based lighting solution we saw in a previous movie. We've got the sun size here. Bring that up. If we crank it way up to, like 100, then we can see that it's taking up part of the sky there. Let's set the sun size to four. Below that we have the ground albedo. That's the brightness of the light bouncing off of the ground.
We can increase that brightness a little bit. Click on the color swatch. And drag the value up. Bring it up all the way to one, and we see we're adding quite a lot of light. Let's set the value to 0.5. We can close the color selector. The ground albedo only gives global illumination into the scene. The ground itself doesn't render. Below that is turbidity, which is the amount of haze. Let's increase that up. Drag that up to a value of 10 or so, and we get a lot of haze.
A good value for this shot would be about 2.5. If you want to tint the color of the sun in the sky, you can do that with these color swatches here. But I'm going to leave them at their default of white. That's how to use the Arnold physical sky environment to simulate daylight with a sun and sky.
- 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