quadratic decay???

[trybul]

what happens when you move the light close to the object that you are trying to light, is it still just black.

what i am thinking is happening, is that, your light does not have enought "power" to light the object once you apply the decay to it. So in this case you will have incease the power of the light, or move the light closer..

it takes a while to get the hang of how decay on lights work, but once you experiment you should get the hang of it..


trybul

[Anteru]

I agree with trybul. Try setting the light intensity to a huge value... (1000 times more). If everything is white then, your light was to weak.

[clarix]

well guys the light is close enough and I already increased the intensity, it renders and in the renderview it shows just black, however when I check the alpha, the alpha seems to be fine.:annoyed:

[Ovi]

1) as far as i know, your alpha will always show objects, even if they are not lit by any light (in 3ds max that is)

2) with your quadratic setting, the formula is like this: intensity = power / (radius*radius)

so if radius is 1, you'll get full power, if radius is doubled you'll get 1/4 power, if radius is tripled you'll get 1/9 and so on.

So if your light works with linear (I = P / R) and no decay (I = P), then your problem is distances in your scene, and light values - the math should work quite well ;)

hopy you'll make it work out somehow :thumbsup:

[ZeroNeuro]

Quadratic lights require a really high intensity value. Like if you use linear and things are fine with an intensity value of 20, then try a value of 200 with quadratic fall off.

[indianBoy]

when does one exactly decide where to use what kind of decay in a light? i havent studied lights, but i can guess it as

*u need a high rate of decay ( like quadratic ) in light sources like LEDs, where the light should only be visible, but should not effect other objects in the scene...

*u need a moderate rate of decay ( like square ? ) in light sources like a cell phone screen where it should only light objects near to it like a hand


*other categories?

please refine what i have said, tho i doubt if any of it is correct

[RoarK]

sunnyboy, allow me to teach you,

LEDs are simulated by using self illumination, the actual light intensity is very low.
in CellPhones u can use self illuminated panel with a minimal glow to it.
dont try explaining real world objects wrt decay of light and dont get caught up in jargon, understand the concepts, decay of light is a realworld phenomenon:

"In the real world, light diminishes over distance. Objects far from the light source appear darker; objects near the source appear brighter. This effect is known as attenuation(or decay).

In nature, light attenuates at an inverse square rate. That is, its intensity diminishes in proportion to the square of the distance from the light source. It is common for attenuation to be even greater when light is dispersed by the atmosphere, especially when there are dust particles in the atmosphere, or fog or clouds." - 3dsmax5 help documentation

hope that answers your question
ciao

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