Natural daylight with Sun Positioner - 3ds Max Tutorial

- [Instructor] Realistic natural daylight is super easy to set up with the physical sun and sky environment. It's controlled via the sun position or helper. I've got a scene here with no lights, no environment, and no exposure control. Let's see what this renders like. Go into the perspective Viewport menu, click on the Shading menu, which is currently labeled standard, switch that over to active shade using Arnold. And that will take a moment to update, once it does, we see the default lighting. If there are no lights in a scene, then both Nitrous and Arnold, will render the scene with a default light attached to the camera or viewport. All right, I'll turn active shade back off again. To fully control a physical sun and sky environment, we need a sun positioner. That is a helper object, not an actual light, but it's found in the lights section of the Create panel. Go to lights, and in the photometric category, you'll see a button labeled Sun Positioner. Click on that button, then go over to the top viewport. Click and drag to create a compass rose, release the mouse button, and then without holding the button down, move the mouse cursor to set the orientation of that compass rose. If I want North pointing in the positive y axis of the world, then I'll move the cursor up above the compass rose in the top viewport. Click to set that orientation. The creation tool is still active. Now move the cursor again without holding down the mouse button, that will set the distance parameter of the Sun positioner. That's just the distance of that light icon away from the compass rose. It doesn't affect the lighting, it's merely for visual feedback in the viewport so we can get a sense of where the sunlight is coming from. Once you set that distance, click to complete that sun positioner object, and then right click to exit out of sun position or creation mode. And with that sun position are created, two things have happened. One, we now have a physical sun and sky environment installed. And two exposure control has been enabled. Let's take a look. Go into the rendering menu and select environment or exposure control. They'll both take you to the same place, which is the Environment and Effects dialog. And the Environment tab we now have an environment map the physical sun and sky. Additionally, in the exposure control section, we see that physical camera exposure control is enabled with an exposure value of 15. As I mentioned previously, exposure control and Max is problematic, due to the tone mapping curve that is destructively applied to the final rendering. That curve is seen if we scroll down a little bit here, image control, we can adjust these values, even if we think that we're setting this curve to a linear response, it's actually never linear, and we can never achieve a raw output as long as exposure control is enabled. To avoid issues with color correction in post, our only choice here is to disable exposure control. So I'll go back up here, and set the Exposure Control Pull Down to no Exposure Control. With exposure control disabled, our rendering will be overexposed. However, just as we can adjust the intensity of a photometric light to compensate for exposure, we can also adjust the intensity of the physical sun and sky environment. To do that, we'll need to open up the Material Editor. Open the Material Editor, and then drag the environment map over into the Material Editor view, choose instance, click OK, and now we can close the environment that affects dialog. Select the physical sun and sky environment node to display its parameters, and we can adjust the intensity here. However, unfortunately, Nitrous does not fully support the physical sun and sky environment. So although we have an intensity value here, we cannot see how it affects the lighting unless we render an Arnold. So if I bring the intensity down to .5, we don't see any change here in Nitrous. So let's go back to an active shade rendering, switch that back on again, that will take a moment to update once again, as it compiles the shader, now we can see that it's quite overexposed. Let's bring the global intensity down to 0.02 and press Enter. And now we've got a well exposed shot in our active shade rendering. Physical sun and sky has many other parameters to play with, such as tint and saturation, but I'll leave those for you to explore. I'll close the Material Editor. Let's make sure that we have focus on the perspective view and the son position or object is selected, if perspective is not the currently selected view, then right click in that viewport to select it, then go over to the Modify panel. In the sun position or parameters, we can adjust the position of the sun in the sky using the date and time mode. There are three modes, date, time and location, whether, data, file, or manual. The default mode is date, time and location, and that's appropriate for real world lighting studies. We can plug in a particular location on earth by clicking on the button here Location on Earth, and we get a map where we can choose a city, for example, I can click on the map here and choose Portland, Oregon. Click OK. And now we're seeing the daylight effect of this particular location, at this particular date and time, so that's really helpful for accurate lighting studies. This is showing us the daylighting on a perfectly clear, sunny day, which may not be the case in Portland, but we can see that like all seen environment maps the physical sun and sky provides lighting and a renderable background. In our perspective view, let's Dolly back with Ctrl + Alt and middle mouse, and then orbit around with alt + middle mouse. So we can see that there is a renderable background, we can position the view with the middle mouse button, and again orbit with alt + middle mouse and we can see that there's actually a sun up there in the sky too. Let's undo all those movements with shift + z and go back to our previous framing. To manually art direct the daylighting, we can switch the date and time mode over to manual. And down at the bottom, is a section labeled horizontal coordinates. Asmath is the rotational angle around the compass rose and altitude is the angle above the horizon line or the height in the sky. Click and drag these spinners to move the sun around in the sky, ff we set the Asmath to 220 degrees, the sunlight comes from camera left. If we set the Asmath to a lower value like 120 degrees, then the sunlight comes from camera right. Altitude is the angle above the horizon line. If we bring the altitude down to a lower value, such as 35 degrees or so, then we'll get the slanting rays of late afternoon. If we bring it down to a very low value such as 20 degrees, we'll get the classic golden hour shot. That's how to use the sun positioner to adjust the physical sun and sky environment for daylighting.