This function allows the user to simulate
the real color of parts according to light conditions in eta/DYNAFORM. An
object itself is not luminous, and it is usually illuminated by three types of
light: Ambient, Diffuse and Specular. The light source is formed by various
lights with different intensity and none of them is purely formed by one type
of light.
POSITION
This function enables the user to uniformly move a
light source direction with a consistent intensity. The dialog box is shown in Figure 15.3.1. The right and left arrow buttons are utilized to
move the light source in the positive and negative X-direction, respectively.
The up and down arrow buttons are utilized to move the light source in the positive
and negative Y-direction, respectively.
Figure 15.3.1 The Light Source dialog box.
AMBIENT
The ambient light
does not come from a specific direction. It comes from a light source, but the
light reflects everywhere in the room or scene, without direction. For the
object illuminated by ambient light, the surfaces along all directions are
illuminated evenly. The user can control the intensity of ambient light using the
slider on the interface.
DIFFUSE
Diffuse light
comes from a specific direction and is reflected evenly on a surface. However,
the object surface directly illuminated by the light is still brighter than the
surfaces swept by light from a certain angle. The user can control the
intensity of diffuse light using the slider on the interface.
SPECULAR
Similarly to diffuse light, the specular
light also has direction. Its reflection angle is very sharp and is along a
specific direction. High intensity specular light tends to form a bright spot (speckle)
on the illuminated surface. The user can control the intensity of specular
light using the slider on the
interface.