This paper introduces a generative design tool for the early design phases. The tool is a prototype plug-in for 3D studio max, based on 3dmax script language. This plug-in generates form alternatives with symbolic representations. Designer sets max and min size values and positional relation rules for different sub-parts of the whole form. After the generation process designers can apply transformation modifiers and materials built in 3D Studio Max to the picked alternative. And get possible 3D form solutions that meet with the constraints of the design problem.