It seems no matter what I do, bump maps have no effect whatsoever in Iray..

It works with 3delight but when I use Iray, nothing happens at all, not even with the most extreme settings. It's not a displacement map, just a simple bumpmap.

With 3Delight it works even with subtle settings

Are you using the Iray uber shader?

Bump works, it just works differently.

In most Renderman (which includes 3Delight and to a lesser extent Firefly among others) render engines Bump gives you an apparent amplitude based on the setting. In most other render engines (to include Iray and Carrara) bump is based on relative size of the UV islands compared to the surface area they take up.

The 3Delight to Iray conversion converts to a smaller value because it can, and does, cause seams on the textures for figures like V4, and Genesis 3.

For Iray, or Carrara or others, If it is one UV island, or the ratio is 1 to 1 then just turn up the bump. If there are multiple UV Islands and they are different material zones then the bump will need to be adjusted individually.

Note this, usually, does not have the same problem when you use Normal Maps instead of bump maps.

It's only one material zone, and multiple UV islands. The strange thing is that I get no bump at all, even if I turn the values to extreme settings, (Settings that make it look insane in 3Delight) I am a bit new with this program, as I am making items better compatible with DS, from Poser, which is where I do most of the work first.