Sorry for my bad English)

I want to use data from 3-axis accelerometer to position cube in processing through serial port.

It is ok when i use 2D (tilting line). But when i write third argument in function "size" - P3D   (size(600, 500, P3D);), processing writes "gnu.io.PortInUseException: serial madness" and many other bad words. 

How can i solve this problem?

Thanks =)