Thanks a lot guys, but none of the above ideas work, I created a brand new object with only 1500 polys, and made a copy of it for the proxy --> red. I can't use the idea of submaterial to select a texture with physicalize option due to the fact that I have more than 1 texture for the entire building...

this is an exemple for a simple building, and I have no idea how to reduce mesh to keep all details of windows, doors and stairs

Thanks a lot for your comment, I can just tell you that my building has 11000 poly in max and no way to know the poly in Cry.
I will try to split the building in separate objects and for each create a proxy.

Hello everyone, I created a complex building with 4 floors, around 80 windows, 50 doors, outside and inside walls. 1 step: the proxy was the exact copy of building 2 step: the proxy is split for the different floor and each of them are imported separately as a single object But every time the buildi...