Datavideo TVS-2000A Instruction Manual page 63

Light
There are four types of light and they are ambient, directional, point and spot. You are allowed
to select up to five lights with each light having configurable parameters.
Ambient Light
Directional
Directional light is basically used to simulate lights transmitted from afar to light up the scene
and other object models. Just like the sunlight rays, the directional light rays travel in parallel
and the light strength will not be affected during zoom in and zoom out, therefore it is more
appropriate for simulating wide range lights, such as lights from the sky, supplementary to the
ambient light and etc. The only variable of the directional light is the angle between the
direction of the light ray and the object model on which the light is hit. The smaller the angle,
the smaller the area of the object model on which the light is shone and the shorter the
shadow. Relatively, the bigger the angle, the bigger the area of the object model on which the
light is shone and the longer the shadow. The user is allowed to select the light color and its
direction.
The ambient light refers to Omni-directional light rays from
a point of light. You are allowed to configure the total light
output strength (Power). Color and direction cannot be
adjusted. Because the ambient light does not create dark
shadow, so it is usually used as a supplementary light for
simulating indirect lights.
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