ChromeStar posted at 12:34PM Sun, 14 February 2021 - #4412730

Bigger area lights produce more light. I just tried changing the scale on a spot light, though, and it didn't seem to make any difference at all.

Regarding Attenuation, look in the light properties, below where you select whether it is a spot, point, infinite light, etc. It's the bottom setting. The default is Constant, which means the light is providing the same amount of illumination regardless of distance. Easy to work with, not very realistic in most cases. There is also an inverse linear, in which case it falls off linearly with distance, and inverse square which falls off with the square of distance. If you want the light to fall off with distance, pick one of those two -- inverse square is generally more realistic.

Oh yeah, now I know. So long since I used it, I completely forgot. Thanks!

That's helpful. Guess, pngs it is then.

ChromeStar posted at 8:03PM Sat, 13 February 2021 - #4412549

Scale definitely affects the amount of light for area lights, not sure about spots

that's what I thought, and I just naturally thought it was like the sun - the bigger the light, the lower the brightness..

ghostship2 posted at 8:02PM Sat, 13 February 2021 - #4412566

@AcePyx you never tell us what attenuation you are using for your spot light. That would affect this greatly.

Hey Ghost, I don't even know what attenuation is, and I certainly haven't changed it from one to another. What does it do?

bagginsbill posted at 7:57PM Sat, 13 February 2021 - #4412520

You're asking about illuminance (how intense is the light arriving at a surface) as a function of distance AND size (scale) of light source, keeping all other things equal.

The lighting equation has many terms but we'll use a simplified one where the variables are roughly just the ones you were changing.

Letting I stand for illuminance, B stand for the brightness of the light source, R is the distance to a light source, and S is the size (scale) of that light source we have

I = B (S^2) / (R^2)

In English, the illuminance is proportional to the brightness of the light, the square of the scale, and inversely proportional to the square of the distance.

Your first case you claim the distance is 10. But the coordinates you gave (z10 y10) would make the distance roughly 14. As well you didn't mention an x offset but I can clearly see that the light isn't lined up on the Z axis so I'll assume x10 as well. Therefore the distance squared (R^2) is 10^2 + 10^2 + 10^2 or 300.

I = B (100^2) / 300 = 33.3 B

Your second case we have z1000 y1000 and I'll assume x is still 10 (looks that way based on the pattern of specular highlights and shadows). This gives a distance squared (R^2) of 1000^2 + 1000^2 + 10^2 or 2000100. You also said the scale is now 10000.

I = B (10000^2) / 2000100 = 50 B

50 is bigger than 33.3, therefore we expect the figure to be brighter.

However, I didn't verify my assumptions about the lighting terms in the version of Poser you're running. There COULD be a bug or other factor I didn't take into account.

For example, I'm not absolutely sure the brightness of the light source is unaffected by changing its scale. If it is, then I'm missing some of the correct equation.

That's an invaluable insight Baggins thank you. I had no idea it worked that way. Now I can adjust the formula to achieve roughly similar values as distance increases. Really appreciate this.

hornet3d posted at 7:53PM Sat, 13 February 2021 - #4412605

ghostship2 posted at 6:53AM Fri, 12 February 2021 - #4412565

Maybe this is the same problem as the infinite lights sometimes not rendering and then the next render they work again.

OK that explains why I can get a very dark render on occasions but if stopped and the render stated again with no changes the render has the expected brightness. I guess it happens about one in twenty renders but I never manged to pin point as far as the infinite lights not rendering.

Yes, same here. I sometimes moved the camera and the lights worked again. I thought it was a problem with the way the program was handling bounce lighting or transparency as I only ever noticed it on indoors scenes. Good to hear your take on it.

ghostship2 posted at 7:52PM Sat, 13 February 2021 - #4412565

Maybe this is the same problem as the infinite lights sometimes not rendering and then the next render they work again.

Ahhh, that one's not just me then? Interesting. It's been driving me crazy.

bagginsbill posted at 7:51PM Sat, 13 February 2021 - #4412521

Yikes that is broken.

Yes quite so. Incidentally, really saddened that the SM forum has been deleted. So much of your wisdom lost :'(

ChromeStar posted at 7:51PM Sat, 13 February 2021 - #4412548

Huh. I noticed the shadow blur turning on and off randomly from frame to frame before, but I assumed it was fixed now.

Yes, they did claim that to be the case. I guess not with all lights.

hborre posted at 7:50PM Sat, 13 February 2021 - #4412541

Report it and give them as much info and examples as possible. Attach your findings.

Yes, already done thanks for the recommendation.

bagginsbill posted at 2:43AM Thu, 11 February 2021 - #4412408

Also maps used for anything but color should have gamma = 1

Why is that Baggins?

"Also maps used for anything but color should have gamma = 1"

Why is that Baggins?

"Has anyone else experienced the same issue?" It doesn't do that for me Nova

722 posted at 8:45PM Fri, 05 February 2021 - #4412068

new update renders much faster

Thank you

722 posted at 7:55PM Sun, 31 January 2021 - #4411580

render are slower

Excuse me?