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View Full Version : Point light acting like distant light?



videobear
09-16-2005, 12:55 PM
I wanted some more control of how my spaceship's glowing exhaust plume lit up the back end of the ship, and other nearby objects as the ship zoomed by them.

Added a point light just behind the spaceship.

It lit up the back just fine...but also lit up surfaces on other objects that were quite a ways off...and that didn't even look like they should be able to "see" the light (no line of sight). For example, some surfaces at the front of the spaceship.

So...I enabled inverse square falloff. No change. Made sure all the spaceship surfaces were double sided, so light wouldn't accidentally pass through them. No change. (Note: this is all in Layout's viewports, set to Textured Shaded Solid display mode; haven't verified all these behaviors in rendered output).

This point light seems to be acting something like a distant light. Wazzup with that? :question:

Dodgy
09-16-2005, 06:53 PM
Did you try lowering the Range/Nominal distance value? For a linear fall off light, this value is the point at which the light stops. However, for an inverse falloff light, this is the distance at which the light is at it's value of light intensity (inverse falloff never cuts the light off completely).

So this range/nominal distance will need to be very different figures dependent on the the light falloff type. If you've used a value with linear, you'll need to reduce it a lot to make give a similar effect with inverse.

Integrity
09-16-2005, 07:59 PM
Did you turn on Raytrace Shadows? It should look fine in a rendered output. The OpenGL will not calculate certain things, which will make parts of the front of the ship seem to be lit by it.

videobear
09-17-2005, 09:08 AM
"The OpenGL will not calculate certain things, which will make parts of the front of the ship seem to be lit by it."

That must be it. Thanks! :thumbsup: