Adobe Director Basics

ADOBE DIRECTOR BASICS
3D: Controlling appearance
If only one or two vertex points are lit, then the other vertices appear dark; the lighting creates a gradient across the
face. This is only an issue with spot lights. A spot light produces a cone of light. One vertex of a face may fall inside the
cone while the other vertices fall outside it. If a face is particularly big and if it is directly in front of the spot light, the
face can fail to light up at all. The cone of light can miss all three vertex points, even if the middle of the triangular face
is directly in line with the beam. To see a demonstration of this effect, download the movie SpotTest.dir.
A spot light lights up faces whose vertices are within the cone of light
The SpotTest.dir movie shows a plane model that is perpendicular to the camera and to a spot light. Using the mouse
you can change two parameters:
The distance from the plane to the spot light by moving the mouse pointer horizontally.
The spotAngle of the spot light by moving the mouse pointer vertically.
The red line across the 3D sprite indicates the combination of distance and spotAngle at which the corners of the plane
are just lit. If the mouse pointer is above or to the left of this line, the corners of the plane model are not lit, and the
spot light fails to light the plane completely.
When you launch the movie, the plane's modelResource has only two vertices horizontally and two vertices vertically.
In other words, its only vertices are in the corners. If you move the mouse pointer below the red line, the plane model
will be fully lit. If you move it above the red line, it will not be lit at all.
You can create a more graduated response by dividing the plane into smaller triangles. The screenshots above shows
which triangular faces will be lit by a particular cone of light from a spot light.
SpotDecay
Even with fairly small faces, the edges of the cone look very hard and rough. You can soften the edges by setting the
spotDecay property of the spot light to TRUE. The following screenshots show the same distance and spotAngle
settings as in the screenshots above, but with the spotDecay set to TRUE.
Last updated 8/26/2011
128