I've spent the last hour or so wracking my brain trying to figure out why this set of props doesn't want to receive light.  Any ideas what might be happening here?

Here's the mat setup...  All are pretty much the same except the ambient values decrease as the objects are farther from the camera.

Open the image maps' preview boxes, so I get an idea of what the math nodes are doing.

Open the image maps' preview boxes, so I get an idea of what the math nodes are doing.

Here you go...  Ambient and reflection values seem way too low to be overpowering the light...  And it's not the light falloff either.  Moving it closer to the objects doesn't help.

Could it be the image map wired to the second value of the math node causing the problem?                                                                                      

I just wanted to add that this doesn't seem to be a Firefly problem, as they don't seem to receive light in preview either.  I added a HR square to verify the light is on and should be reaching them.

Here's a wireframe view.  These objects were imported from Wings3D.

     What about the properties in the parameters panel? 

 flipped polys? happens sometimes on import.

     What about the properties in the parameters panel? 

Don't see anything strange there either...

 flipped polys? happens sometimes on import.

All objects were created from the original imported mesh.  In the 1st and second pictures you can see the top side of the shapes correctly lit by light.  When the polys are flipped in the group editor the objects appear lit from below, so they aren't flipped.

I saved them as a prop and loaded them into my default scene, just in case the lights were to blame.  If I change the ambient material to "0", the object appears completely black.  All are completely unaffected by lights in both texture shaded preview and firefly.

It's the math node plugged into the diffuse channel...  If I change it from "multiply" to "add" the objects is properly shaded again...  Weirdness.

     The "Light Emitter" box should be ticked, unless you have some specific reason to not do so.

     With that top math node set to add, open its preview box so we can see the result of the math operation.  You might also edit the node titles;  there are a lot of appended underscores and digits.

     The "Light Emitter" box should be ticked, unless you have some specific reason to not do so.

     With that top math node set to add, open its preview box so we can see the result of the math operation.  You might also edit the node titles;  there are a lot of appended underscores and digits.

I'm not using IDL, so I didn't think they needed to be set as light emitters...  I actually need to render each object individually as elements for a 2D parallax effect, so I specifically don't want them lighting each other indirectly.  The underscores came from copying the initial material as the objects were cloned multiple times, I wish they were all cleaned up, but it's not causing any problem that I know of...  Anyway, this wasn't necesarily the effect I was going for, but it shows that they all now render properly.  The light is a point light just behind the metal ball, which is my focal object.

Changing it back to multiply removes diffuse/specular from its appearance in preview and Firefly.  Oh well...  Movin' on...

You have a multiply node, but vast swaths of the lower map are zero, which will give you a diffuse and specular value of zero for those areas.  Try putting in a math node adding a small value such as  0.2 to the lower map and see what happens...

You have a multiply node, but vast swaths of the lower map are zero, which will give you a diffuse and specular value of zero for those areas.  Try putting in a math node adding a small value such as  0.2 to the lower map and see what happens...

Somewhere between setting it up and running into the problem it worked as intended.  The lower map was supposed to multiply the top one.  Where the area is white the rocks would be more pronounced, and as the area turns black they would be blended out.  What Poser has no way of showing in this room is what part of the material preview square falls into the object's UV space.