Hi. I hope this is the right place to ask this question. IBL lights are a must for quality renders in Poser and i"m trying to understand precisely how they work. I hope this isn't a stupid question.

 I've placed an IBl light with an image map in a scene. I added a ball that has reflections on. Why isn't the ibl light reflected in the ball. The other props and characters are reflected on the ball. 

As i see it, the IBL light is a dome light that surrounds the scene and "sends" the image of the image map onto the scene from all directions. I know it's different from a spot light. An image map attached to a spot does send the  image onto the scene in a direct manner coming from the source of the light. I expected the IBL to send the map in a spherical manner.  It sure doesn't seem to work that way. Is it because it is an infinite light that is too far away to send a precise image? The colors are sent. I guess it's because of the diffuse aspect of the IBL setting. What does the diffuse mean in reference to the ibl lighting? Why don't I see the colors in the 100% reflective ball? On a non-reflective ball, you can see the color variations on the shading.

The upshot of this is,is that the resolution of the image map should not mean very much. If only diffuse color information is being sent, the image map can be very low res. the only reason to use HDR images therefore is for the greater color depth. I really don't see the point of the hdr maps anyway as the effects of the additional colors are very, very subtle. I can't believe that the difference is visible.

I'm sure there's a simple answer and i'm missing something obvious. Help would be appreciated

Mike

You might want to have a look for some posts by BagginsBill about IBL and HDR lighting.  I'm not sure you are entirely correct in your assumption about the dome light bit - I seem to remember you need to create an actual skydome in Poser for it to work that way.

IBL lights don't have a specular component.

If you want to use the same image as a reflection map, use a sphere_map node connected to the Reflection_Color input.

Please see:

http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2747230

Get GenIBL and my Environment Sphere. All will be revealed.

By the way, you cannot use the same image both for IBL and for Sphere_Map reflection maps. They must be laid out differently. The IBL image must be in "Angular Map" format. The Sphere_Map or my Environment Sphere must be in "Equirectangular" format. The GenIBL tool will let you capture a modeled 3D surround or (using my environment sphere) an equirectangular image as an angular map image in Poser, using no other tools.

I did add an spere map to the reflection node and the effect is what I want, but it feels like cheating to just add an image map to an object. I probably could have added the image to the color node as well. Sorry, but I missed the point of the lack of specular component in IBL lights. Does this mean that they don't put out highlights or brightness? I just don't think it should work that way. Do other 3d programs treat ibl the same way?

Bill, I'm still working on your reply. I'm not sure that I'm precise enough to care if the image on the ball is not the exact same as the ibl, since the ibl effect is way to subtle for anyone to even begin to see the difference. Only you and I will know! It is intellectually interesting to know the difference though.

Thanks for all your help.

Mike

Other 3D programs do not treat IBL the same way. They take it a step further. Built into those tools is the envelopment of your scene in a giant virtual sphere with that image attached. Then that sphere is consulted in reflection and the specular lighting effect and the diffuse lighting effect.

Poser only uses it for diffuse lighting effects.

If you use my environment sphere, you can also get Poser to use it for reflections.

The last (and very important) component, the specular lighting effect, is a problem. The only way to get it, as far as I know, is to use a blurred version of the panorama and attach it in the material of an object, with the Sphere_Map node.