— Menu —

Don't just accept the default sun and background settings.

You can always do better by adjusting most render settings to your unique scene.

The default settings for sun and background (sky) may not be ideal for your particular scene. I'll suggest an alternative setup that might be a good start to better 'model your models'. Before we start let's review some of the Adobe Atmosphere Sun settings:

Sun Orientation

First, the sun's orientation in your scene: (with apologies to Adobe for using their figure)

Better Sun Cone Angle

Below is a little sketch which I hope will allow you to visualize what a 'cone angle' is. It shows a big (or near) yellow light, and its large cone angle, casting a big blurry yellow shadow - while a small (or far away) red light, with its small cone angle, casts a smaller and sharper red shadow.

Improving on the Sun default settings

Below is a 2D image of an easy to duplicate sun test, made with 11 default cubes. The test object sits 1 cube height (2 feet) above 9 cubes that receive its shadow. One additional cube can act as a fill light. In this test, all values (except face sample size) are defaults.

Default Settings

1. The default sun is at 45° elevation, meaning that it lights the front face 'B' and the top face 'A' equally. That is to say that it is exactly half way between horizon and zenith. The result is no visible difference between the front and top faces.
2. The default sun azimuth is 0° and the cone angle 0.5°, so the side, back and bottom are not lit by the sun. They would be equally black, if not for the light from the background (sky).
3. The default background is quite bright and diffuse, so it lights all but the front and top faces to exactly the same level seen on face 'C". Again, the result is that all those face blend together. One could say that rather than shading the cube to make it appear as 3 dimensional as possible, the default settings actually camouflage the cube! Ideally, none of the cubes faces should the same tone.
4. And what about shadows? The rendering is set for the default 'Final' mode, so the sampling size, etc. should show shadows, depending on the sample size of the top faces of the 9 light colored cubes. All the cubes except '1' and '2' are set for 0.1 to show shadows (default is 1.0). Face '1' is set for 0.01 and face '2' for 0.2. However, all of that bright background light washes out the shadows - they become invisible. So, even though we pay the price of extra long rendering time for changing the face's sample size from the default, we still don't get our shadows. (See the sampling density discussion below)

Below is the same test setup with one possible way of getting more flattering forms.

Custom Settings

1. First, I turn off the background calculation for light and shadow. It's best to do this in both the 'Settings' tab of the 'Light Control' and for individual objects or faces in the Player View 'Object Inspector' 'Light Map' tab.I also make the background darker, but since its light is ingored, this is not really necessary.
2. I raise the brightness of the sun to 4 (from 1) to lighten the scene and get a white on the top faces of the 9 cubes. I also lower the sun's cone angle from 0.5 to 0.01 for sharper shadow edges.
3. To make all faces of the test cube different tones to enhance modeling, I move the sun up to 70° to differentiate the top from the front. I likewise move the sun to an azimuth of 30° to make the sides of the cube different.
4. With such a sharp cone angle and no background 'ambient' fill light, the back and sides of the cube are black. The bottom gets some reflected light from the tops of the 9 cubes, so it is not black. Anyway, I add the fill light cub and set it to emit light, to fill one side and the back.
5. With no background to wash them out, and a smaller cone angle, we now get sadows. Notice that the 0.1 sample size gives good shadows, the 0.01 ('1') seems to be overkill and the 0.2 ('2') is too big to get sharp shadows for only a 2 foot cube.
6. Another approach, without using a fill light, would be to set the cone angle so high that sunlight reaches around the sides of the cube. A setting of 60° to 90° would work - but that would also stop you from getting shadows.

Sampling Density settings for objects and faces

'Sampling Density' lets you control how large the smallest areas you are willing to use to calculating the light rendering should be. If you choose a smaller number (more samples per object), you get a higher resolution rendering - but at the cost of longer rendering time - possibly much longer. If you choose a larger number, such as the default, rendering will go faster, but your smaller light effects and shadows will be invisible. You may also get 'light leaks' around walls, since the wall might then be too thin to offer a significant sample.

Besides the 'Sampling Densities:' setting on the 'Advanced' tab of the 'Lighting Control', shadow rendering also depends on the 'Samplling Density:' of your faces or objects in Player View, on the 'Light Map' tab of the 'Object Inspector'. This is a great tool, because you can set the sampling density high on only those faces or objects where you expect fine detail or need shadows to show. This gives the best trade off between rendering time and rendering detail.

The default setting of 1.0 will not show shadows for default sized (2 foot cubes, etc.) models. A setting of 0.2 just starts to show fuzzy shadows of a 2 foot default cube at 2 feet from a surface and a setting of 0.1 gives good shadows. A setting of 0.01 only sharpens shadows a bit and is probably overkill, since it could greatly increase rendering time.

Alternate Sun Settings - My 3D version to explore

---