Cannot see bump map that is applied to inside face of glass when viewing from outside

[stevesideas]

Is there a solution to this ?

I have a thin box which is the glass panel. The bump map is applied to the inside face. I cannot see the bump map no matter what I do when viewing from the outside!?

Ive tried turning on "reflect on backside".

[vlado]

Is there glossiness for the glass? Is the option "Show map on back" enabled for the bump map?

Best regards,
Vlado

[stevesideas]

No, glossy is set to 1.0.

I did find out though that when I applied the bumpy glass shader to the inside faces, the IOR of the interior of the room through the glass from the other side looked completly wrong. Almost as though id created a plane with a glass shader applied so that there was no backface...like looking through water (if you understand what I mean). The bump map was completely ignored. Does that mean I would have to set the IOR of the facing side (without bumps) to an IOR of 1.0 ? I'll give that a go.

[vlado]

So you have one VRayMtl material for the front and back faces, or two different materials?

Best regards,
Vlado

[stevesideas]

Two different vray materials.

[vlado]

Hm, it might be worth trying one material with different maps (e.g. through VRayMultiSubMap, or through mapping the front/back sides to different UVW places).

Best regards,
Vlado

[stevesideas]

Thats working now I think. Thankyou very much !