Black Render

[broozee]

According to the bug list, light decay works. I'm using spot lights with linear decay and a multiplier of 10,000.

Why do my images render black?

Bill

[bdcali_cg]

Black Render

How far away are your spot lights? If they are too far, the light decays before the object can be illuminated.

Here are some very basic tests with a spot light and the 3 different decay types.


Linear: Multiplier=50


Inverse: Multiplier=50


Inverse Square: Multiplier=50[/img]

[broozee]

Black Render

bdcali,

Thanks for the response - I think you might have solved my problem. My units are inches and my spot lights are approx 1,200 inches from the 0,0,0.

I'm working on an exhibit design that is 20' x 50'. From your tests, it seems as if spot lights based on the units I'm working in (inches) is not the right combination?

Bill

[FOG Lite]

Black Render

The different test images are very helpful as well!

[bdcali_cg]

Black Render

Your units are fine, but how far is the spot from your object? Not the 0,0,0.

The spot light I'm showing is only 5' (60 inches) from my object (Object size: 1'-10"x1'-3" or 22"x15"). If your fixture is 1200" from the object you are illuminating, I'd suggest moving your spot closer. Or else give the light an ungodly high multiplier. :P

[broozee]

Black Render

bdcali,

I've attached an image showing a simplified example of my trouble.


In oder for the spot light to show any light using linear decay I would need a
multiplier in the range of 500,000. Like you said, this is an ungodly high.

Does this mean the size of the spot light is independant of the multiplier? Meaning the over all size of the spot light determines how hight the multiplier has to be?

With that said, this tells me is that spot lights are not the correct light source for a model this big?

[bdcali_cg]

Black Render

It probably good to think of it in real world terms... You're trying to light something roughly the size of a small house, with a light 100' away. It might not work.

You may want to consider using the directional light with a multiplier around 1(performs like the sun). If that doesn't meet your design intention, perhaps you might try more spot lights closer to your object.

Does this mean the size of the spot light is independant of the multiplier? Meaning the over all size of the spot light determines how hight the multiplier has to be?

Thats a good question, I haven't tested that out with spot lights personally, but it seems to be the case.
However Area lights (rectangular lights) size do seem to affect the intensity of the light.

Has anyone else found this to be the case?

[broozee]

Black Render

bdcali,

You are right - I need to think in terms of the real world. I've played with the directional light before and it worked great - just like you said, multiplier of 1.

My only objective with the spot light is for soft shadows. So an object this size, rectangular lights (for the softshadows) or directional lights seems to be the better choice.

I am curious as well if anyone else has discovered the spotlight / multiplier relationship.

Thanks for the discussion. It really helped me figure some things out.

Bill