Modélisation procédurale par composants
The realism of computer graphics images requires the creation of objects (or scenes) of increasing complexity, which leads to considerable costs. Procedural modeling can help to automate the creation process, to simplify the modification process or to generate multiple variations of an object instance. However although several procedural methods exist, no single method allows the creation of all types of complex objects, including in particular a complete building.  This thesis proposes two solutions to the problem of procedural modeling: one solution addressing the geometry level, and the other introducing a general system suitable for complex object modeling.    First, we present a simple and general modeling primitive, called a block, based on a generalized cuboid shape.  Blocks are laid out and connected together to constitute the base shape of complex objects, from which is extracted a control mesh that can contain both smooth and sharp edges.  The volumetric nature of the blocks allows for easy topology specification, as well as CSG operations between blocks.  The surface parameterization inherited from the block faces provides support for texturing and displacement functions to apply surface details. A variety of examples illustrate the generality of our blocks in both interactive and procedural modeling contexts.  Second, we present a novel procedural modeling system which unifies some techniques into a common framework.  Our system relies on the concept of components to spatially and semantically define various elements.  Through a series of successive statements executed on a subset of queried components, we grow a tree of components ultimately defining an object whose geometry is made from blocks.  We applied our concept and representation of components to the generation of complete buildings, with coherent interiors and exteriors.  It proves general and well adapted to support partitioning of spaces, insertion of openings (doors and windows), embedding of staircases, decoration of façades and walls, layout of furniture, and various other operations required when constructing a complete building.
Procedural modeling Component Architecture Building Shape grammar Boolean operation Geometric representation Subdivision surface Bloc Block