Lighting, Light Options

The previous sections discuss attributes which are applied to the surfaces of a part to change the way that the part will be displayed in a shaded mode. The next set of information deals with changing the environment of the display rather that the part in the display.

Ambient

The Radiant Light presented in the previous section is a way of "raising" the overall color of an object by a means other than a light source. The Radiant Light method is one where it is applied to surface(s) of a part and is part of the definition of the part. It is like the part "glows".

Another way to achieve the same result is through the use of Ambient on the Lighting Options form from the Lighting form. Ambient is trying to simulate the non-directional environmental light. This is the kind of light that might exist outside on a heavily overcast day. There is light in the environment, but it has been so scattered through the clouds that there are no shadows cast. The light is of equal intensity from all directions.

Ambient is a percentage between 0% and 100%. Similar to Radiant Light it again refers to the percent of part color which will be visible regardless of any directional light. The big difference between Ambient and Radiant Light is that Ambient is a characteristic of the environment whereas Radiant Light is a characteristic of the part. The following pictures show Ambient set to 0%, 15% (the default) and 50%. Note that all parts are affected by this change, not just the Sphere as in the Radiant Light illustrations. Note also that the sphere in these three images is identical in appearance to the sphere in the Radiant Light images. Again, the difference is "glowing" surfaces versus environmental lighting.

Exposure

Exposure is intended to simulate the f-stop on a camera. That is, the scene can be made lighter by increasing the Exposure (opening the f-stop) or it can be made darker by decreasing the Exposure (closing the f-stop). The reason for allowing this is that in some very complicated lighting situations, where many light sources are being used, it can often happen that the general lighting display is acceptable with the exception of the overall lightness or darkness of the display. A simple "tweak" of the Exposure fixes the problem without trying to adjust light source intensity or position.

Exposure is not implemented properly in Master Series. It should be a fractional value that can be less than one or greater than one. Unfortunately, the user interface is such that only integer values of Exposure between 0 and 100 can be set. This means that either you see nothing (Exposure = 0), as in the following example...

Or you see what you had before you adjusted Exposure (Exposure = 1)...

Or you see a very overexposed image (Exposure = 2)...

As far as I am aware, the technology is still in Master Series to get a "proper" exposure setting, the only problem is the interface to capture the data from the user; it is limited to integer values between 0 and 100 and that is not the correct user interface for the Exposure value.