A form for optimization is created by a spring-particle system, with gravity forces, damping, attraction and particles' mass integrated within the system. The structure is based on inverted gravity principle to derive the final form. Fitness objective is that certain points in space - which represent light sensors placed in physical environment, that are constantly taking measurements of light levels - are reached by corresponding points attached to the structure. Required form is achieved by adjusting mass of each particle and rest length of each set of springs. These parameters are in turn encoded in form's genotype. Changeable light levels corresponding with points are reflected in weights attached to fitness function. The fitness function is evaluated once the whole spring system gains stability, as it acts dynamically in time. In optimization process two various dynamic aspects play an important role in finding satisfying solution - physical movement of the structure and constantly changing fitness function.