The qnswer to my question is probably "no", but I'd like to make sure:

Is there a way to tone down or completely remove highlights from one light source, without affecting the highlights from another?

to make things clear, here is the setup:

One shiny object very prone to highlights.

2 light sources at somewhat different angles and of different color.

Problem: Right now I get 2 prominent highlights of 2 colors. I'd like to get rid of one highlight without getting rid of the light source that's causing it. What can I do?

I'd very much appreciate your help with this. Thank you.

If the second light is for lighting the scene, but the object doesn't need it, you can set the light to light everything except the object. That is on the properties tab.

If you want to remove all the light from a particular source, you can use the Restrict Lighting to function for the light. It's on the General tab/section of the properties panel.

If you want to control the specular and diffuse component individually, we offer a plug-in called Lighting Control in the Shader Plus package that lets you adjust Specular and Diffuse contributions of individual lights as part of the object's shader. You can get more details at

http://www.digitalcarversguild.com/plugin.php?ProductId=13

Regards,

To answer the questions: I do want both lights to illuminate my object, I just don't wish to see the highlights from both.

Eric, thank you! I have Shader Plus, and I never looked at the Lighting Control before (how stupid of me!). I have a question about it thougth:

There is a known issue with Carrara, and that is that when you are using proper GI (light Sky light) and you have a Sky Dome (and actual model of it) in the scene, even when your Sky Dome is set NOT to cast shadows, the GI will not penetrate it, and will be obscured by it completely.

Is there a way to counter this problem with the Lighting control somehow? I notice it has GI settings, although I don't exactly understand what that means. Or maybe it can be done with some other plug-in from your shop?

Oh, and another question for Eric: with the Lighting Control, I would have to set it for every shader of every object on which I'd want differential treatment from different light sources. Is this correct? There is no way for me to select a bunch of shaders and apply this to all of them at once, or to set this globally if I need the highlight from different sources treated differentially, but in the same fashion throughout the scene?

Antaran,

You are correct. There is no way to set it globally.

Regards,

Oops, missed your first question. I don't think Lighting Control will help with the modeled sky dome blocking GI problem. The slider on LC will let you adjust the intensity of the GI lighting for that shader, but only if it gets to the object.

Regards,

Eric, is there any chance that you would consider expanding the functionality of the plug-in to have a sort of a master preset. Right now if another light is added, or if there are a lot of objects in the scene with a lot of shaders, the task of managing it all becomes quite laboreous and full of many tedious repetitions. Setting up a master preset that could be edited for all the shaders it covers and adding shaders to it in groups (we can select multiple shaders in the shader room) would be a huge improvement.

And if more of batch setups were included, it could be something like a Shaders Plus 2, which would be a new plugin with the new price tag on it.

Thank you for the GI clarification. Let's hope that DAZ gets around to fixing that onw on their own.

I think this is something we all need to petition DAZ about; Carrara desperately needs specular/diffuse settings on all its lights. Seriously, this is an industry-standard feature that even Poser and Daz Studio offer! There are countless everyday lighting approaches that require specular/diffuse lights and you can't do 'em in Carrara without a lot of messing around.
That being said, Shaders Plus is your best bet. Lighting Control and Selective lighting are 2 things I can't live without!
JT

I agree. If you open a feature request overr at DAZ, please post it here, so we all could add our voices to it. I can do it if you don't want to, but you seem to know more about his issue than I do. Just let me know either way.

Quote - Eric, is there any chance that you would consider expanding the functionality of the plug-in to have a sort of a master preset.

It's something I've considered and I have on my list of things to investigate.

Regards,

Quote - It's something I've considered and I have on my list of things to investigate.

I am very happy to hear this! I hope it turns out doable and worth your time.

as ment abv, poser can set diffuse/specular color separately for lites in material room.  somebody may wish to set spec=black or diff=black on a poser lite, then see if carrara imports the lite correctly.

for black spec, poser exports "KsColor 0.0 0.0 0.0 1" and/or

nodeInput "Specular"
                    {
                    name "Specular"
                    value 0 0 0

 carrara may or may not be able to read nodes for poser lites.

Antaran-
There may already be a feature request about this over at DAZ. There was some debate in the DAZ forums a few months back; strangely there didn't seem to be much interest in specular lights; everybody was blabbering on about cloth simulators and fluids solvers when it came to "must-have" features :)
If you open up a request let me know; I'm part of quite a few Carrara groups and I'll definitely spread the word!

Your request concerning having a modeled sky dome with a separate GI sky light source has been an issue that I've wanted forever.  My interest has always been a little different.

I would like to have a background/atmosphere that would provide light for the GI and a background/atmosphere that would be rendered into the image.  For me, this has been useful for space scenes.

I would like to use StarBright for the star backdrop but I would like to use a b-gradient for the lighting.  At best, I have to do two renders and combine them for animations.  I can use a backdrop for single scene renders but it's only for single images.

I tried, carrara pro can't import a poser diffuse-only lite.  on export, a carrara file (readable as text) contains no discernable info on specular and diffuse components of lite, but only info such as color and intensity.

This is a render with two light sources.  One is just a normal bulb light.  The other is a glowing spher set to a glow value of 2000 using indirect GI.  I rendered this with the setting jacked up for quality so there is a price for using this idea.

1.)  It's limited on how it impacts the scene.  In other words, you don't have a lot of control of things.

2.)  Even with the setting pumped way up, there are still limits to the artifacts that can appear.  You can jack stuff up a lot more than I have here and get the quality even higher but you will pay for it in render time.

Anyway, this is an option that can be used for two light sources which produce two significantly different highlighting results.

Basically, I think you will get better results using the DCG plug-in.  It really depends on how much energy you're willing to pound into an image.

I think indirect GI can be used for different types of highlights in many scenarios. The lights with different specular and diffuse settings are usually used to simmulate indirect lighting/bounce lights, so they are used to avoid the render time expense of the indirect lighting calculations.

But I think your method is wonderful for what I've been describing above -- about the modeled sky dome. I just tested it and it gives very good results: I can set the same map to the glow channel, as I do to the sky dome color, I can use the ShaderPlus plug in to set the sky dome's shader not to receive any lighting or shadowing itself (and thus cut down the render time a bit) and I can render with indirect lighting only (no need for sky lighting) in the GI section upped to about 250% for a very realistic effect of the sky light emmited by my skydome. (No need to increase the glow value in the shader even, just an incrased indirect lighting effect). On pretty decent quality settings the render time is a bit expensive -- 1:15 minutes for my very simple scene (1 sphere, 1 plane, 1 sky dome hemisphere, no other lights whatsoever), but it does give a nice result, where something like this is needed.

Quote - Antaran-
There may already be a feature request about this over at DAZ. There was some debate in the DAZ forums a few months back; strangely there didn't seem to be much interest in specular lights; everybody was blabbering on about cloth simulators and fluids solvers when it came to "must-have" features :)
If you open up a request let me know; I'm part of quite a few Carrara groups and I'll definitely spread the word!

I found this feature request and have already added my support to it: https://bugs.daz3d.com/view.php?id=36350

The more supporting issue notes there are on the feature request, the greater the chance that DAZ will pay atterntion and start working on it. So please add your supportive comments and spread the word to get better promotion for this request.

While I see the resons for people wanting to have cloth syms and fluid syms rigth there in Carrara (animations mostly), I think this issue is of equal importance: being able to animate requires the ability to animate faster and specular-only diffuse-only lights are an essential part of that optimization. I think this should be made clear both to DAZ and to Carrara users.

I also have a bug report about GI ignoring don't-cast-shadow settins, so please add your support to it as well, if you believe it should be fixed:

https://bugs.daz3d.com/view.php?id=39886