I need a software to measure dimensions of cross sections from JPG

[vinod006]

I need to measure the cross sections of cars, chemical plant equipments, instruments, Isometric photographs of Piping Layouts of Plants to have design data.

 

[Dr_JRE]

There is a free and open source 3D modeling / animation studio that can do this.

Blender
http://www.blender.org/download/get-blender/