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Poser - OFFICIAL F.A.Q (Last Updated: 2024 Dec 23 7:38 pm)



Subject: Poser Slippery Lights Mystery


moushie ( ) posted Wed, 07 March 2001 at 9:04 PM · edited Wed, 25 December 2024 at 9:00 AM

I've one overhead light. It's parented to nothing, it "points to" nothing, and it's locked. Yet the moment I begin rendering, the light flips to dead-on. Cancel the rendering and it promptly reverts to overhead. Every time. Que pasa, and what can I do? (This forum has never ket me down yet.)


ScottA ( ) posted Wed, 07 March 2001 at 9:35 PM

Cut and paste your preferredState.rsr to a temp directory. Then open Poser and see if it fixes it. If it didn't you can always put that pz3 file back in the prefs folder. No harm. no foul. Each light has an .rsr file for it as well. You could try doing the same thing with those. ScottA


Huolong ( ) posted Wed, 07 March 2001 at 10:17 PM

ScottA - not sure I understand what you're saying. I was just about to post the same question. I just am getting around to using lighting (got tired of weird results so I turned off shadows). The problem is that no matter where you set the lights up manually, Poser moves them around according to a process dubbed: LightLogic (LL). LL does a line of sight (LOS) calculation to determine the optimum placement of lights behind props, below floors, etc (called LOS Defilade [LOSD])to ensure that the center of attention (COI) is darkened and the maximum amount of inappropriate shadow (IS) is cast. LL should be modified to produce less LOSD and IS.

Gordon


ScottA ( ) posted Wed, 07 March 2001 at 10:40 PM

Oh. I see. I thought he was having trouble with lights that used to work. But don't now. The advice I gave was geared towards finding out if something got corrupted. Not how the lights actually work. ScottA


Huolong ( ) posted Wed, 07 March 2001 at 10:44 PM

Yeah ... I've read some posts here about reducing the shadow and posting additional lights, but there's another dimension, new paradigm, horizon, floor, vision ... at work here other than my usual fevered imaginings.

Gordon


Nance ( ) posted Wed, 07 March 2001 at 11:27 PM

Hmmm - never heard anyone describe this moving lights problem before - and now two? Q's: Spotlights or Global? What makes you believe the light is directly overhead prior to rendering? (which of the various indicators are you looking at to determine position?) When you said "flips to dead on", did you mean the lightsource appears to move to the camera position?


Huolong ( ) posted Wed, 07 March 2001 at 11:36 PM

I haven't done a full diagnostic yet, but at least on light flips down to a line focused at the center of the image, but not necessarily head on (like tail on). The shift comes during render and when rendering is finished, the lights pop back where you left them (like roaches when the lights go on).

Gordon


JKeller ( ) posted Thu, 08 March 2001 at 12:22 AM

You may already know this, you may already be way ahead of me on this, but I figured I'd point it out anyway. One thing you might want to look at: from the right menu below the view port, select Shadow Lite1 Cam (or 2 or 3, etc.) under the Cameras sub-menu. You will switch to the POV of light 1 (or 2 or 3, etc.) With this, you can see exactly where your light is aimed. If you want to adjust your light at this point, make sure you actually select the light prop itself rather than the Shadow Lite Cam.


Huolong ( ) posted Thu, 08 March 2001 at 8:28 AM

Didn't know about the POV thing, but it doesn't address the issue of the lights jumping around. Will try to determine which lights move. Not all do.

Gordon


moushie ( ) posted Thu, 08 March 2001 at 9:58 AM

Hi. Have just got up and read these messages. Not quite sure what to make of them. For clarification: When I'm ready to render, my sole light, a spot, is pointing down. Nothing precise about it, just down. It's visible, obvious, and the way I want it. When I render, I see the light in the little globe at top left suddenly flip to center-on; on completion, it flips back up again. The render shows dead-on lighting, not overhead.


ScottA ( ) posted Thu, 08 March 2001 at 10:09 AM

I can't get this to happen. Could you delete any figures you have in the scene. Then save it as a .pz3 file. Then e-mail it to me? I'd like to see if it's something in the scene settings. ScottA scotta@rochester.rr.com


moushie ( ) posted Thu, 08 March 2001 at 10:12 AM

Maybe it was a corrupted light after all. I deleted it, saved, re-opened, and created a new light, which worked fine. New mystery though. This spot light doesn't cast a shadow. Both it and the large table which is the target of the light are set for "cast shadow", but there is none.


moushie ( ) posted Thu, 08 March 2001 at 1:51 PM

Well, I've learned one thing. Maybe I should have known. Only Lights 1 and 2 cast a shadow, and when I had only one light it was a number 3, the others having been deleted. That explains the no-shadow mystery. I've noticed a light flipping again while rendering and can easily duplicate it, but it seems to be some other light than a Number 1 or 2, in which case the shadow is unaffected. I hope you followed all this. Thanks for the help. Poser lights are temperamental to say the least.


bloodsong ( ) posted Thu, 08 March 2001 at 5:55 PM

um, guys... you may notice that poser changes the light position icons depending on which camera you are in. ie: if you have a light from the front, it's in front on the front camera, to the right on the left camera (front of your scene) and to the left on the right camera (front of the scene). right? so... when poser makes a shadow map, it uses the 'light shadow camera' right? and if you're 'in' the light shadow camera, you see the light from dead-on, right? well, the point is, your lights aren't jumping, that's just poser jumping into the light to render the shadow map. don't sweat it. :)


Huolong ( ) posted Thu, 08 March 2001 at 6:51 PM

If that's the case, I would expect the whole view to change to the camera parked coax with the 'light shadow camera', nez pas? Y'all

Gordon


Nance ( ) posted Thu, 08 March 2001 at 9:24 PM

Try slapping these values on your Light3 and see if you don't get a nice white overhead light pointing down on anyone standing at the center of the universe. Light 3 0 Angle Start 0.0000 Light 3 0 Angle End 35.0000 Light 3 0 Dist Start 0.0000 Light 3 0 Dist End 0.0000 Light 3 0 Point At 0.0000 Light 3 0 shadowStrength 0.6000 Light 3 0 depthMapSize 1024.0000 Light 3 0 xrot -90.0000 Light 3 0 yrot 0.0000 Light 3 0 zrot 0.0000 Light 3 0 scale 1.0000 Light 3 0 RED 1.0000 Light 3 0 GREEN 1.0000 Light 3 0 BLUE 1.0000 Light 3 0 INTENSITY 1.0000 Light 3 0 xtran 0.0000 Light 3 0 ytran 2.7000 Light 3 0 ztran 0.0000


Huolong ( ) posted Fri, 09 March 2001 at 1:14 AM

file_152833.jpg

Took a while to catch one of the slippery little devils, but, live and on camera ... in living color. Observe the positions of the lights during render and after. The lights quickly hid behind the booth, and jumped out just after rendering leaving the artist trying to figure out why the shadows weren't where they were supposed to be.

Gordon


moushie ( ) posted Fri, 09 March 2001 at 10:05 AM

Bravo! The smoking gun. My problem exactly. Anyone got the explanation -- and solution?


bloodsong ( ) posted Fri, 09 March 2001 at 10:27 AM

heyas; and i bet that light at the top there is 'light 2,' right? poser is in that light's shadow camera. the scene doesn't change, because the scene is still in the main camera, or whatever you're using. poser is in the light's shadow camera, busily making the shadow map (as it says). try going to render options and turning shadows off, see if it still 'jumps.'


moushie ( ) posted Fri, 09 March 2001 at 11:24 AM

That's all very well, Bloodsong, but when Poser does its thing through the shadow light it changes the shadow light's position, so the shadows don't render as intended. Sounds wrong to me. And rendering with shadows off to prevent the light moving, if that's the case, isn't going to solve anything.


Huolong ( ) posted Fri, 09 March 2001 at 12:44 PM

Right, tlmoulson ... that's exactly why I don't use shadows in most of my work... can't predict the outcome.

Gordon


moushie ( ) posted Fri, 09 March 2001 at 2:39 PM

That's hardly consoling, but I guess it's the answer. Thanks.


Nance ( ) posted Fri, 09 March 2001 at 6:51 PM

Bloodsong seems to have identified this correctly as a non-problem several posts back so let me ask it this way. Which shadow in your rendered image appears to you to be in the wrong place? The one easiest for me to see is the one on the bench from the figure's thigh, and it appears to be correctly cast from the overhead light. If your shadows were generated from a light "dead-on", that one would not be there. I'm afraid I still do not see what makes you think the light sources are actually moving when rendered.


moushie ( ) posted Sat, 10 March 2001 at 11:34 AM

file_152835.jpg

I originated this question, and that image wasn't mine. Here's what my rendering of a table looks like. Light 2 was the sole light and it was overhead. It was set for shadows, as was the table. I don't know how to show you an unrendered version, but just believe me, the single light was overhead and it flipped during rendering. Try it yourself.


Nance ( ) posted Sat, 10 March 2001 at 2:57 PM

OK, It looks like you are using the default ground plane which does do funny things with shadows. It also appears the front left corner of the table is the point directly under the light. The shadow falling to the right is logical if your light were close and the Falloff Start and End values are set very far apart - making the shadows soft-edged and cast outward. Try the same scene with a square prop instead of the ground plane and try the values for light 3 as posted above and see the difference. (I haven't moved my Geo site so I cannot post an image right now) Or,select your light 3 and hit Copy and come over here and paste the values in a post and let me see if I get different results perhaps.


Nance ( ) posted Sat, 10 March 2001 at 3:10 PM

Ok, grabbed some cyberspace. First pic tries to copy your problem:
r1.jpg
Light 3 0 Angle Start Spline 0.0000 Light 3 0 Angle End Spline 160.0000 Light 3 0 Dist Start Spline 0.0000 Light 3 0 Dist End Spline 0.0000 Light 3 0 Point At Spline 0.0000 Light 3 0 shadowStrength Spline 0.6000 Light 3 0 depthMapSize Spline 1024.0000 Light 3 0 xrot Spline -90.0000 Light 3 0 yrot Spline 0.0000 Light 3 0 zrot Spline 0.0000 Light 3 0 scale Spline 1.0000 Light 3 0 RED Spline 1.0000 Light 3 0 GREEN Spline 1.0000 Light 3 0 BLUE Spline 1.0000 Light 3 0 INTENSITY Spline 1.0000 Light 3 0 xtran Spline 0.0000 Light 3 0 ytran Spline 0.6000 Light 3 0 ztran Spline 0.0000 Next - the shadow I assume you are trying for.
r2.jpg
Light 3 0 Angle Start Spline 0.0000 Light 3 0 Angle End Spline 35.0000 Light 3 0 Dist Start Spline 0.0000 Light 3 0 Dist End Spline 0.0000 Light 3 0 Point At Spline 0.0000 Light 3 0 shadowStrength Spline 0.6000 Light 3 0 depthMapSize Spline 1024.0000 Light 3 0 xrot Spline -90.0000 Light 3 0 yrot Spline 0.0000 Light 3 0 zrot Spline 0.0000 Light 3 0 scale Spline 1.0000 Light 3 0 RED Spline 1.0000 Light 3 0 GREEN Spline 1.0000 Light 3 0 BLUE Spline 1.0000 Light 3 0 INTENSITY Spline 1.0000 Light 3 0 xtran Spline 0.0000 Light 3 0 ytran Spline 2.7000 Light 3 0 ztran Spline 0.0000 Note the differences in the Y-Trans and AngleStart & AngleEnd values, and again, second pic uses square prop rather than Ground.


Huolong ( ) posted Sat, 10 March 2001 at 5:43 PM

Nance - what you are describing is a bit over my head. 1. It appears that the jumping lights is nothing to worry about, it's normal. 2. The number of variables affecting good lighting seem to be more complex than other aspects of normal Poser capabilities (morphing, texting, transmaps, etc). Do you recommend a tutorial on lighting? The manuals only help after I have figured out the basics for myself the hard way.

Gordon


Nance ( ) posted Sat, 10 March 2001 at 7:17 PM

Attached Link: http://nance.excelland.com/Tutorial_Softlight/SoftlightTutorial-Nance00.html

No No! Sorry! It looks more complicated than it is. And perhaps WAY more complicated because of my copy&paste. That was just the easiest way to show the values on that light's dials because I couldn't post a screen-capture. I believe you cannot see your shadows because the edges are too feathered out, too soft. Essentially, I am suggesting that you use a smaller cone of light (Angle Start dial =0.0, & Angle End dial= 35.0)to make your shadows with harder, less feathered, edge transitions and then raise the light farther overhead (ytrans dial = 2.7) to compensate for the smaller pattern cast from the now smaller cone of light. Try it with just those two changes and see if you don't get something more like the second image. I don' seem to bees 'splainin this very well -- so this may not help much either - but here's a few, very rambling, observations (complete with circles and arrows) that touch on some aspects of Poser lighting & shadow controls: [ Poser Softlights](http://nance.excelland.com/Tutorial_Softlight/SoftlightTutorial-Nance00.html)


JKeller ( ) posted Sat, 10 March 2001 at 11:31 PM

That's a great tutorial, Nance. It's true that things like this seem complicated on paper (or html), but I think as soon as anyone starts applying your techniques in their own scenes they will see how easy it is.


moushie ( ) posted Sun, 11 March 2001 at 12:32 AM

For me, explanation complete ... mystery resolved ... case closed. I have experimented and duplicated Nance's results; all is crystal clear now. My gratitude to all who have graciously responded, not least of all to Nance. As stated at the outset, this forum has never let me down.


Nance ( ) posted Sun, 11 March 2001 at 8:11 AM

Success! Woohoo!! Ellery Queen gots nothin' on me! ;-)


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