Surface Modeling Tool

GENR8 is a surface modeling tool using biological growth mechanism which is basically based on map L-Systems. It is currently available only as a plug-in of Maya which is high-end 3D modeling software. GENR8 was invented in terms of interactive design process, so that various parameters are available in order to generate and search surfaces. Attractor, repeller, gravity, repelling points, random noise, boundaries… etc. Such parameters might be roughly categorized into four groups which are external influences, grammars of growth system, types of EA, and fitness functions. Due to variation of parameters, totality of surface proliferation is massive and infinite. In such four categories, external forces are the simplest and traditional parameters. Figure 2-1 shows examples of surfaces produced by GENR8 with external influences. In the left case, a surface is attracted by gravity and disturbed by a sphere in the same way of the real world. Meanwhile, in the right case, cylinders magnetize a surface in relation to the distance between a surface and attractors.

Figure 2-1: Examples of growth model in GENR8 with external forces.
Source: O’Reilly and Hemberg (2006)


On the other hand, other three categories of parameters are remarkable points in GENR8. It might be claimed that users are not able to control whole system of form findings in other traditional applications because of their deterministic algorithms. That is to say, initial setup is the only possible manipulation, and generative process is not modifiable. Unlike such design tools, in GENR8, users are applied to access every stage of surface growth and search. Although some growth grammars are given as default settings, it is possible for the user to write a grammar by him/herself.


As far as concerned about evolutionary computation, GENR8 equips a grammatical evolution (GE) developed by O’Neil and Ryan in order to search not simple design solution, but alternatives of surface. GE is extended standard genetic algorithms, but it is more similar to biological processes. Meanwhile, the considerable point is not GE itself, but the way to use GE in the tool. Users are able to choose a specific type of GE from given lists, and each GE has different features. In aesthetic design, one of the most difficult elements about EA is a fitness function. Although mathematical functions are very useful in the case of optimization, it is difficult to explain human sense as exact mathematical functions. Therefore, Interactive Evolutionary Computation (IEC) is used for fitness function in GENR8, which tries to predict user preferences. Users can set the several parameters at the beginning, and it makes IEC judge user preferences. In the same way as the list of GEs, fitness functions are parametrical factors in GENR8. In brief, components related to EA can be seen as a tool in GENR8. This is another conspicuous and significant feature of the tool unlike other design applications. Such approaches to evolutions reduce human fatigue and make the access to the tool easier even if one is not an expert of computer programming.


As demonstrated above, GENR8 is an innovative design tool due to its growth system and evolutionary algorithms. Nevertheless, no environmental parameters including lighting factors, wind dynamics, sunlight and so on, are currently available. It is because GENR8 is created as not an optimization tool, but an aesthetic surface modeling tool. On the other hand, its abilities of surface generation as a tool itself are extremely powerful and potential. The concept of user interfaces and convenience as a design tool is particularly significant. Therefore, in terms of exploitations of environmentally optimization and design tools, the way to equip environmental parameters in the tool as an advanced version might be a next important factor. Such concepts are also useful for individual design cases.