Has anyone got this to work...? The manual says that you can set the distance where the light starts to falloff and the distance past which there is no light. What are the units of distance..? How far is 1..? I can't figure it out. Can anyone help..? Ian

Have you tried it with the spotlights?

Yes......I'm only trying it with spotlights. (and I'm using Poser 4 + PPP) Ian

I'm assuming the units that the falloff uses are equal to the units that you X, Y or Z trans parameters use. Therefore if your light was set with a Z trans of 10 and your subject had a Z trans of 0 and your falloff was set to 10, the light would start to fade at the point that it reaches your figure.

Aw- come-on, that would make it much too easy. The falloff dials are using some value other than the screen distance units used by the translation dials. It works pretty well, you just gotta find the range. I've not played with it enough to explain a relationship between the distance and the value on the dial. I generally set the start and end values the same, and adjust them until the subject pops into ,or out of, the light pattern. From there, you can then back the two values off to create the actual falloff effect range. Here are some values that ought to get you in the ballpark: Oh yeah, because you cannot see the effect until rendered, finding that magic starting point requires a lot of guess&render, tweak&render, nudge&render, etc.

Nance, my method of lighting is more, seat-of-pants style. I just play around with the lights until I get the effect I desire. However, I read your tutorial on soft shadows and have been reading your posts on lighting, and I've figured that if I paid a bit more attention to the details of the lights, I could probably achieve my desired effects using fewer lights...therefor my animations don't take so long to render.

So I've been playing around with distance falloff tonight. And if the units that fall off uses and the units that x/y/z trans uses are not the same...then what am I doing wrong?

I'm not trying to challenge what you said. You obviously have spent more time than I have with this. I'm just wondering what part of this I'm missing.

Well, it looks to me as if the distance falloff does use the same units as all other measurements. (I read somewhere that 1 unit = 8 feet.) Look at these screenshots: the squares are at Z=-1, -2, and -3, the light (represented by the flashlight prop) is at Z=0. (The red text was added to the screenshot later to label the distances, the lines are approximate.) One thing blurring JKeller's test is the angle falloff he's using; I've set them to be identical so the spotlight gets a sharp edge. First off, if Distance End = 0, the effect is shut off, regardless of the setting of Distance Start. The light is at constant intensity along the entire length. The second example shows Distance End at 3; the light falls off gradually, and the third square is not lit. In the third example, Distance Start is at 2, and if you look carefully you can see the gradation of the falloff between 2 and 3, whereas the light is constant intensity before 2. I forgot to include a screenshot with Distance Start = Distance End >0, but in this case you do get a sharp edge. The "take home message": To get a graduated falloff, Distance End has to be set for a somewhat larger value than Distance Start. If Distance Start = Distance End (and > 0), you get a sharp cutoff of the light at that point -- great for getting a spotlight effect on a figure in the foreground without casting a shadow on objects behind. That's what's happening with JKeller's example above.

Thanks guys.......I now understand how Distance falloff operates. Petercat: your explanantion is excellent. Thanks again, Ian

heyas; wait... does that mean that distance start is... oh, that's where it starts to fall off? that's X distance from the light, right? so is distance end the distance from the light, or the distance from the start?

As far as I understand it, both distances are calculated from the light itself.

hmmmm... (render,render,render) Ok, sounds good, but still a couple of seemingly inconsistent results that I could use some help with. First, my previous diagram above was calculated using the Front camera. (I know, bad idea) When you guys mentioned getting predictable results using normal screen units I tried it again and to my surprise, I got different lighting results when the same scene was rendered with the Main camera in approximately the same position. What rendered as lit from the Front camera -- came out unlit from the main camera without any other changes in the scene. The point being that choice of camera may affect lighting results. Ok, just forget the front camera issues for now, its goofy and nobody uses it for real renders anyway. With regard to the values in the DistStart &DistEnd dials being standard Poser screen units, consider the following:

Falloff Occuring at Distance Greater than Dial Setting

DIAG #2: -light at 2.700(z), -front surface of stairs at 1.000(z), -front surface of large box at 0.000(z) -DistStart=0.650, DistEnd =0.950. Expected all objects to be UN-LIGHTED as both DistStart and DistEnd values were less than the distance to the nearest object. Results: ALL LIGHTED???, but clearly working, with falloff starting at about the second stairstep and ending at the front of the box. As stated before, though I can get the results I want, it just does not seem quite as predictable as previous posts suggest. No biggie, but if we suggest that this stuff is simple and predictable we're gonna drive nubies crazy. The fact that using Poser screen units as a basis for the settings on this dial did work in petercat's illustration, appears to be coincidental and cannot be applied, as my second example shows, as a general rule. If they were standard Poser screen units then I should have gotten the above result with the values DStart=1.700 and DEnd=2.700 not DStart=0.650 & DEnd=0.950. Just reporting differing results. Can't explain it. As JK asked: "What part of this am I missing" also? Here's the .pz3 (about 100K) if you want to reproduce these results yo-own-self: Lighting Falloff PZ3.zip -Nance ...still in the dark (BrainFog Start=0.000 BrainFog End=0.001)

problems with pz3 .zip at STAS.net. Don't DL just yet.

i'll stick to default poser spotlights, and render in vue if i wanna get tricky! oy! :) here's a freaky one to consider... does the camera focal length have anything to do with it??

ooooooooh... a troublemaker eh? dunno about the focal length, but you wouldn't think so. (runs back to Poser to render same file just posted to make sure) CRIPES! Changed focal length from 110 to 35 and falloff zone moved somewhere else entirely. Question sounded preposterous (why would zooming the camera change the relationship between light and obj) but thats got to be the difference between the results we were getting. I believe you nailed it bloodsong. Thanks Mam! JKeller and Petercat, what length lens were you guys using in your renders? o.t. btw-can't get .zip's to work at stas.net and have to click everything else two or three times. Now even the .jpgs won't load. Grrrrrr! With the recent rash of TOS changes, anyone have current suggestions for freebie webspace still suitable for these forums? Thanks again .....bloodsong. (you realize of course that there is no suitably endearing diminutive form of "bloodsong")

Yup! Looks like using Poser standard units will work in the DistStart&DistStop dials if your camera is set somewhere around 35mm! Longer camera lenses, with the same falloff dial settings, move the affected zone farther from the light. Or, as you zoom the camera out, the falloff zone moves toward from the lightsource. Dollying the camera seems to have no effect. (gonna make that Hitchcock/Spielberg "dolly-zoom" move difficult!)

I was using the Main Camera as it loads default: 38mm.

I suppose if you were going to do the Hitchcock (Spielberg steals the technique and uses it on a closeup and he gets a credit?) dolly-zoom move you would have simply have to animate your fall-off distances relative to the animation of your focal with matching keyframes. That or use another program with more straight forward lighting.

Mighty peculiar. The trick to doing tests like these is to change as few variables at a time as possible, and note the differences. What seems to be happening here is that the falloff is interacting with the **scale** of the camera -- which Poser changes on its own (along with the camera position) when you change the focal length. It must be how they simulate the focal length effect, since the camera doesn't really have a "lens" to adjust. Nance's example file had the camera's focal length at 110 and the scale at 300. Once I set them back to 35 and 100 (the default, and the settings I used in my tests previously), the falloff worked as expected, as shown in the top screenshot. I've added some measuring sticks (stretched square props) to help indicate the distance: 0 is at the light location (z=2.7), the others at whole unit positions as shown. The front of the steps prop is at z=1 (1.7 units from the light), while the "wall" is at z=0 (2.7 units from the light). I've also pasted in a shot of the light settings, which are the same in all screenshots. With Distance Start = Distance End = 2, the light reaches the top couple of stairs, but not the measuring stick at 2. Then I changed the focal length to 70. Poser altered the camera position and scale as shown in the second screenshot, and you can see that the falloff pattern has also been altered. According to the manual, the camera "scale adjusts the dimensions of the studio in the window." That is, it seems to act as a **multiplier** for the dimensions. That's why the falloff is changing: at 200% scale, the falloff settings are effectively 200% of what the dial shows, or in this case, 4 -- as shown in the third screenshot, with the steps moved back by 2 units. As in the second screenshot, the light reaches the top part of the stairs (at 3.7) and cuts off before reaching the measuring stick at 4. In the fourth shot, with the steps back in the original position, I reset the scale to 100, and the falloff was back to the same as in the first screenshot: the light reaches the top couple of stairs, but not the measuring stick at 2. So to get predictable results, be careful to ensure that the scale of the camera is at 100%. If you want to do a "vertigo effect" (which I believe is the name given to Hitchcock's effect, since he first used it in the movie "Vertigo"), as JKeller said, you'll have to animate the distance falloff -- if the falloff is important in the scene, otherwise just set them to 0 to shut off the effect. At least now there's a way to calculate what they should be. So, set the first frame with the camera at 100% scale; set the last frame at the desired focal length, note what the scale is, and multiply the distance falloff start and end by that percentage to get the numbers for those settings in the last frame. Another funky thing I've noticed, if you change one of the default infinite lights to a spotlight, both distance falloff dials are created with maximum limits of 1, so if you have "Use Limits" checked in the Figure menu, it won't let you set them above 1. Just double-click the dial and enter a high maximum value, if you don't want to shut off limits (which may affect your poses). If you create a new spotlight, the maximum limit is set for a very high value already. By the way, I didn't know this stuff before -- I've learned it over the past couple of days in working out this puzzle and figuring out why we're seeing these effects.

heyas; yes, that's me, a trouble-maker. ironbear said so in one of his reveiws. anyway, yeah, it seems completely bizarre that the light falloff would hav ANYthing to do with the camera focal length. however, since you mentioned discrepancies in using the front camera (a parallel camera) and the main camera (a conical camera)... the thought occurred to me. and, basically, it's no weirder than ik-chained feet moving as you adjust a figure's hands, or the light icons popping around as you render.... and that's okay... i dont particularly care to be called diminutive things. ;) (how about bloodiddlydo? naaah...!)

Where can download a helix staircase? I wanna try something.