Our concluding example demonstrates the simulation of a complex plant scene. Here we applied some of the previously discussed instancing methods, in par- ticular the approximate instancing procedure, whereby the terrain from Fig. 7.7 serves as a basis. The parameterized data base of different species is generated using the Xfrog modeling system (see Fig. 8.15). […]
Category: Digital Design of Nature
Texture Synthesis for Nonperiodic Tilings
Aside from using the tiles for the efficient production of plant positions, the nonperiodic tilings can be applied in many other places. One example is texture synthesis. For the photorealistic rendering of landscapes often a realistic ground texture has to be used. Here again we want small images that are to be repeated on the […]
Point Production for Nonperiodic Tilings
Similar to the point production on a single repeating tile we have to proceed for a set of tiles. The only difference here is that for computing the Voronoi diagram, the points cannot be repeated cyclically over the tile borders. Instead we have to fit them to all possible points that are on tiles that […]
Aperiodic Tiling
Unfortunately the eye is extremely critical in the recognition of repeating patterns. It will always realize the periodicity of simple tiling, in particular with flat viewing angles, as is evident in the sunflower field from Fig. 8.10b. Here a tile with 160 sunflowers was iterated over the plane. Despite the large number of plants per […]
Instancing of Plant Populations
For a reduction of data, but also especially for lowering the modeling effort, it is very helpful to render a large plant population by combining many equal base elements. Doing so, the region or space that a population usually inhabits, is divided into squares using a plane division method. tiling ^ On each square, i. […]
Section 8.4 Reduction of the Geometric Data image quantization median cut algorithm • : • Figure 8.8 Median cut algorithm: (a) initial partitioning at the median regarding ж-values; (b) areas after a number of divisions with representatives (red panes) at the center of gravity of all points in a box (a) (b) At the beginning of the procedure, the number of areas is defined. After respectively many areas have been generated, the representative is positioned at the centroid of all the points in an area. In a plant population, the representative is thus assigned the attribute and thereby also the respective appearance resulting from the centroid element. Figure 8.8 demonstrates this process.  
Chapters Hierarchical Instancing Modeling Vegetation Instancing can take place on several levels. Thus not only can different plants be represented over a single geometry, but instancing can also be implemented within tree structures: Leaf instancing is used to define a small branch; branch instancing is applied to define a larger branch, and so on. This […]
Reduction of the Geometric Data
The preceding sections focused on the production of individual plant positions and parameters in complex plant communities. For rendering, however, the quantity of the geometrical data must be drastically reduced. The starting point here again is a list L of the plants, which is generated by the simulation models or graphical specification algorithms. L, for […]
Simulation of a Plant Association
A somewhat more intricate model describes the development of a plant association with different species. In [39] open L-systems are used for this process, though simulation can also be programmed in a more simple way using other methods. Each species is described by a number of values. The values include the rate of new plants […]
Simulation of a Plant Population
In Sect. 3.6 we discussed different models with which populations can be simulated. in contrast to the direct specification, here the plant distribution is the result of the production algorithm that replicates the development history of a population. The goal is to obtain a simulation of a population in a balanced condition, and to transfer […]
Chapters Interactive Specification
Modeling Vegetation The interactive specification of plant associations is necessary in all those places, in which by human intervention the natural development of the plant associations is altered. Some examples are gardens, parks, urban landscapes, and large parts of what we call “cultural landscapes”. Thus the specification encloses many different areas that are dealt with […]