Displacement slot value relative to object size?

[SPS]

This is hard to explain but I cannot seem to get a grasp on it on my own...

I'm building a tile roof using displacement maps. Where I would normally use a modifier for this, I would rather make adjustments to the material rather than edit each object's modifier stack. So I placed the bitmap in the Displace slot and set a value of 10.0. I don't know how the maps values translate to units in this case, but 10.0 looked good.

As I began copying variations of the roof planes and resizing them using the slice modifier, I noticed the smaller the object, the less pronounced the displacement value affected the rendered appearance. Does this make sense?

My objects are simple planer, zero-thickness polys with only a UVW Map and multiple Slice modifiers to adjust size.

1.50.SP4a on 2009

[Codi]

Try disabling the "Relative to bbox" parameter. Then the amount value will be directly related to the % you put in the displacement map value. Meaning that 100 in the material displace value equals to the distance amount you enter in the displacement parameter.

[SPS]

Thanks Codi. I found this global setting after my post. It didn't occur to me until reading your reply that I could just set the default value to 100" and then treat my slot spinner as inches for any material. Thanks for clarifying.