I'm working on a render where I need one object to not be affected by certain lights. Is there any way I can do this in Poser, or will I have to correct the shadows/highlights in Photoshop after I render?

It depends on what you're looking for. If you mean you don't want an item to cast shadows from lighting then you can uncheck the cast shadows in the properties section for that item (for figures such as people, animals and such each body part must have cast shadows unchecked). As for anything else I'm not sure how to go about it.

Unchecking Cast Shadows on the object will affect it globally from all lights, not certain lights as mentioned in your OP.  Still, is this what you want?

Seems pretty straightforward to me - Cyberwoman wants to be able to prevent selected lights from having any effect on selected objects. I've wished for that for a long time too, and it's a standard feature in any good 3D program. Oops, I mean any good 3D program aside from Poser. ;-)

No way to do it as far as I know of, but it sure as hell would make dealing with Poser's finicky lights alot easier.

Here is one possible solution.

You could do two separate renders, and save them in a format that supports an alpha channel such as png. The first render would contain all items except the one that requires special lighting, and would be light by all lights. In the second render the special item is added, all other items are hidden or deleted from the scene, and all lights that you don't want to affect the special item are turned off. In a paint program (eg PaintShop Pro, or PhotoShop, etc) you would composite the two images by copying the special item from the second render and pasting it into the first. In PSP you use selections > Load From Alpha Channel, to do this.

If the special item is partially occluded by some other item(s), and also partially occludes some other item(s), the situation is more complex, and you would need three renders, one for the occluding foreground item(s), one for the special item, and one for the occluded background item(s), but the same principles apply.

Poser does not have finicky lights. That is a perception caused by non-linear rendering, i.e. ignoring gamma correction. Sorry - had to say it. By finicky lights people usually mean "does not behave the way I expect real life lights to behave" and this is not the lights it is not using the linear rendering equation and not using falloff properly.

With Poser Pro 2010, the problems go away. Anyway...

Is this request motivated by attempts to produce fantasy lighting or real lighting? Because if it is real lighting you seek, and are asking for hacks to get around some problem with lighting, the solution is the linear rendering equation, not hacks.

If it is fantasy (impossible) lighting you are after, that's a different problem.

I guess what I'm saying here is tell us the problem we're solving. Having a prop that ignores some lights is not a problem - it's a solution for which I'm unaware of the problem. In business software development I hear people ask for a certain feature and I'm not interested. I'm interested in the problem, and I will invent the feature if needed.

I'm not aware of any actual CG lighting problem (real scenario) in which a prop needs to ignore some lights or some shadows.

Quote - I'm not aware of any actual CG lighting problem (real scenario) in which a prop needs to ignore some lights or some shadows.

I've had to do that occasionally, although normally the other way round.  Sometimes you have to give something a little extra light but you don't want to overlight the rest of it so you have a spotlight or whatever linked to the thing which needs extra light and set to not affect anything else.
Vue can do it, Max can do it (and I assume XSI as well) and it would be handy (I guess) for Poser to be able to do it as well - it's not realistic but it does help solve lighting problems.
In that case, linear won't make any difference.

Here is an example of compositing layers. Three lights were used in this scene, one red, one blue, and one green. All lights are in the same position (this is not necessary). Figure 1 shows the scene rendered with all three lights, which together produce greyish colour.

Then three new renders were made, each render had only one light turned on, and only one prop visible. The first render was of the ball, with only the red light turned on, and was used as is (figure 2). The second render was of the box, with only the green light turned on, the box was selected via the alpha channel (figure 3), and it was pasted as a new layer on top of the render of the ball. This procedure was repeated for the render of the cone (figure 4). The result is the combined image (figure 5).

Quote - Poser does not have finicky lights. That is a perception caused by non-linear rendering, i.e. ignoring gamma correction. Sorry - had to say it. By finicky lights people usually mean "does not behave the way I expect real life lights to behave" and this is not the lights it is not using the linear rendering equation and not using falloff properly.

Poser does have finicky lights - when you're going for an effect, that is. And considering the nature of the request, you of all people should have realized it was for the purpose of creating a certain look and not necessarily realism.

Unless you just wanted to take this opportunity to lecture on realism once again, in which case you'd be right. ;-)

Although I'm not the one who asked the question, I am the one who said "finicky lights". For my part, there have been many times when I wanted something in the foreground to be brighter, but had some object in the near background picking up too much light due to the fact that the light in the foreground was affecting it. And more times than I could possibly remember I spent hours trying to get the balance right, to get the effect I wanted.

If I could simply turn off a particular light or lights for that object, it would be a matter of seconds to get what I wanted, not an hour of trial and error - to have an option for every light to affect diffuse and specularity on everything as a default, but to be able to select objects to not affect at all. Inversely, the object could have an option to be affected by all lights or only particular lights in the scene - same result, different means.

This is why other programs have that feature. Somebody must be using it after all. ;-)

subject to some limitations, a posersurface with a texmap or simple colour in alt_diff channel is not affected by the poser directional lites.  e.g. said surface will not receive shadows cast from objects between it and a directional lite, nor will it be illuminated by said lite (subject to some limitations).  place a request in the poser 9 thread for an additional lite property called "restrict lighting to these objects", with all selected by default.

It is for a fantasy lighting situation. I have a glowing energy-beam-cage-type-thing that I need to keep a few bright lights from affecting, because when the light hits the glowing surface it screws up the glowing effect.

I am in Poser 7, so as far as I know I don't have gamma correction settings. While I would love to get a nice new Poser Pro 2010, neither my computer nor my bank account will support it right now.

Right now I am experimenting with using a prop that is invisible, but visible in raytracing and casting shadows to "shield" my energy-cage prop from the lights. Unfortunately I don't know how it's going to work because I don't have time right now to let my computer sit undisturbed and run a render, but I'll probably run one this evening and see how it goes.

Quote - It is for a fantasy lighting situation. I have a glowing energy-beam-cage-type-thing that I need to keep a few bright lights from affecting, because when the light hits the glowing surface it screws up the glowing effect.

Sometimes with glowing translucent beams, you can use Ambient_Color, setting the Ambient_Value to one, and the Defuse and Specular Value to zero. Doing it that way the item is self illuminating, and not affected by the lights in the scene, but whether it will produce the desired results in your case, depends on how you have set up the glow.

Attached Link: Digital Lighting & Rendering, Second Edition

Carrara 6 Pro has selective lights as well. On a quick look, I don't see it in DS, though maybe one of the plug-ins provides it. It's one of the things I keep meaning to try in Vue - I can see how it would make some things easier. If BB or SM would do it for Poser, I'm sure it would be a welcome addition.

Here's what Jeremy Birn (Pixar Lighting TD) says:

"If you have a light that you only want for a specific purpose, such as adding highlights to a character's eyes, then you can use light linking (also called selective lighting), which allows you to associate specific lights with specific objects. You could create a point light, set it to emit only specular illumination, and then link the light to the character's eyeballs. If this light is kept reasonably close to the camera position, you're guaranteed that the character's eyes will always have highlights when it looks toward the camera. And because of light linking, you'd know those highlights won't affect anything else in the scene.

You can also use light linking to gain more precise control over how different objects are lit. If you have a light illuminating many objects in your scene, you might find that it looks good on most of the objects, but somehow appears to light other objects with the wrong intensity, color, or angle. Instead of settling for a compromise, you can make a second copy of your light, and link it to the objects that weren't well lit. Once you unlink the old light from those objects, you can adjust the second light in however you want.

Light linking is a marvelously powerful cheat, but can make an unrealistic image if you aren't careful. Whenever you set up a scene with light linking, you need to test-render it and make sure that what you've done makes sense and doesn't depart too obviously from what's plausible."

The only other method that I can think of to exclude an item from a light, is to use a mask plugged into the lights Intensity node. I tried that once, it worked to some degree, but not as well as I had hoped. To make the mask I set the Background Color to white, then set the Foreground Color to black, then hid everything except the item I wanted to exclude. Then set the Display style to Silhouette. Then I did a preview render through the shadow cam of the light I wanted to exclude. This gave me the black and white image for the mask, which I then plugged into the Intensity node of the light.

Quote - "Vue can do it, Max can do it (and I assume XSI as well)"

*-----------------------------------------------------------

Yes, Softimage can do it, and it works great. :-)

From the Softimage manual:

You can set a light’s selective property to be Inclusive or Exclusive, depending on how you want the light to affect its associated models.

• Exclusive illuminates every object except for those in the light’s Associated Models group.

• Inclusive illuminates every object defined in the light’s Associated Models group.

***-----------------------------------------------------------------------

Quote -
**Here's what Jeremy Birn (Pixar Lighting TD) says:**If you have a light that you only want for a specific purpose, such as adding highlights to a character's eyes, then you can use light linking...

Well, I believe that enough reason has been established, so shall I assume we can expect Poser 9, or at least Poser Pro 2011 to have this feature? ;-)

Just a thought, why not use a spotlight to light the object you want darker with negative light?

Quote - Just a thought, why not use a spotlight to light the object you want darker with negative light?

Generally that's a pretty poor workaround, very hit and miss, very difficult to get just right. Once you add one negative light you find you need more because one can't quite do it, and before you know it you've simply compounded the problem and have also created more lights than OpenGL can display in the preview.

Not just that, but in alot of cases the idea isn't to darken an object, but rather to prevent other lights from affecting it.

See what was quoted above by Jeremy Birn - a negative light in that example would completely defeat the purpose of the effect he wanted.

It depends on your scene complexity though. It can work and I've done it many times, but it's almost impossible to get the exact lighting that simply having on/off otions for diffuse and spec for objects would give

This won't help the OP, who uses P7, but PP 2010 allows you to set gamma correction for individual materials in the Material Room. That is one way to make individual objects darker or brighter in the same lights.

Quote - This won't help the OP, who uses P7, but PP 2010 allows you to set gamma correction for individual materials in the Material Room. That is one way to make individual objects darker or brighter in the same lights.

Well that might be helpful for those times when a darker material is desired....

Hell, if that's all we were talking about here you wouldn't even need GC, you can just do it with a lower diffuse value.

What we're talking about has nothing to do with material settings or how diffuse, bright, dark, shiny or even invisible an object is. It has to do with preventing certain scene lights from having any effect on a particular object.

I'm kind of surprised it hasn't surfaced in Poser yet.  People have been asking for it since Poser 8 (I think - I'm still on 7)

Hey FrankT - remember this thread?

http://www.renderosity.com/mod/forumpro/showthread.php?message_id=3603639

In there I show how to isolate a light to only affect one figure, complete with shadows and all. With any version of Poser since P5.

The main light here hits everything, but only one Andy responds.

Quote - Hey FrankT - remember this thread?

http://www.renderosity.com/mod/forumpro/showthread.php?message_id=3603639

In there I show how to isolate a light to only affect one figure, complete with shadows and all. With any version of Poser since P5.

The main light here hits everything, but only one Andy responds.

 

That's extremely clever, but  what would you do in a more complex scene with more lights? I think by far the simpler solution would be to add the include/exclude feature to Poser's lights. As I said, we've established the "problem" which is what you asked for. ;-)

Speaking of lights, Poser should have photometric lights too and the ability to use IES profiles. All the cool apps are doing it these days. :D

Now you come to mention it yes, I'd completely forgotten about it though!
That would certainly do the job

Thanks for the suggestions, everyone. My "shield" attempt failed miserably, so it's looking like my only options are to live with the light or fake its absence in postwork.

BagginsBill, that is extremely close to what I want to do! The only difference is that I want a light to affect everything but one object. Unfortunately, this is a pretty big scene with lots of materials so I think it will be easier to postwork the lighting than it will be to implement a shader on every other material the light needs to hit :sad: Thank you for the link, though. I will bookmark it, because I'm sure I'll need it sometime in the future.

Quote - I think by far the simpler solution would be to add the include/exclude feature to Poser's lights.

Indeed and exactly.

Poser has a Utility Script that collects scene inventory right. I think if one wanted to they could extend another setting in the Light's Materials to add an Exclude Node.

Love esther

"Hey FrankT - remember this thread?"

Very cool! Though I agree that a built in function would be better than a brilliant hack. It does raise an interesting idea though, selective lighting by object is great, but imagine the addition of selective lighting by material. Seems like you could do some neat stuff with that.

Quote - "Hey FrankT - remember this thread?"

Very cool! Though I agree that a built in function would be better than a brilliant hack. It does raise an interesting idea though, selective lighting by object is great, but imagine the addition of selective lighting by material. Seems like you could do some neat stuff with that.

Agreed, but if they do that they NEED to also include selective objects.

Some objects have a whole lot of materials and it would be a real PITA to have to change the lighting for each one. So if they made it only by material it would be like, "Here's what you wanted, but it pissed us off so much to have to do it that we've decided to make it hard on you" ;-)

yes, superman with light eyes or something

"...Agreed, but if they do that they NEED to also include selective objects."

Ummm, that would be why I said:

"...but imagine the addition of selective lighting by material." :-)

"...superman with light eyes or something"

Yes, for some reason I was thinking superhero as well, although I'm pretty sure that you can do the eyes already in Vue by selecting them as objects - if you don't select group into single mesh on import (at least in Vue 6), all the body parts should be available on the light's include/exclude list.

I was thinking of the trim or insignia on a costume, for no particular good reason, but there are a lot of possibilities. We can already make glowing materials but using lights provides even more flexibility. Not necessarily 'realistic,' but fun :-)