Research

RiverLand: Procedural Terrain Synthesis

RiverLand begins with an empty 2D canvas which represents the top view of the land. The user is allowed to paint regions on the canvas. Within each region, the user is allowed to specify ridge lines, and the heights and widths of various points on the ridge lines.

The procedural terrain synthesis method begins by creating random river seed points on the region boundary. From these seed points, meandering rivers are grown into the region. Tributaries are also spawned from these rivers. Rivers are not allowed to cross user-specified ridges. Once inside the influence of a user-defined ridge, a river grows up in the direction towards the ridge line. Once the river network is established, mountains are grown on the rest of the terrain. Fractal methods are used to introduce interesting variations into the terrain.

 map with color-coded heights and water, generated by procedural modeling

Compared to previous methods, RiverLand has the following advantages: (1) It produces more heterogenous landscapes, with steep ravines, alpine mountains, rolling hills, flat river valleys and cliffs within the same terrain; (2) it produces a globally physically consistent river network, a feature only present in a few of the existing algorithms; (3) it is near real-time, faster than most of the existing algorithms; and (4) it allows users to influence the terrain, a feature found only in some existing methods.

 map with color-coded heights and water, generated by procedural modeling


Procedural Modeling for Traditional East Asian Architecture

We have developed a procedural modeling system to create buildings in ancient East Asian styles. We have formulated a description of the basic elements of traditional East Asian architectures, so that a user can quickly create buildings based on these architectural styles. Ancient Chinese, Korean and Japanese architecture share many common characteristics and yet have fundamental differences. We show that, by varying some parameters, users can conveniently create buildings of the different styles using our graphics modeling library.

In this paper, we show examples of palaces, houses, gates, temples, pagodas, pavilions and fences. With our system, a user can create models of palace, temple complexes and other virtual environments. By setting the dimensions and parameters of a building, the user can create 3D models of most of the existing ancient East Asian building structures, and can also create novel ones using different parameters.

The main contributions of our work include: (1) the formulation of a generalized procedural model that is able to describe a wide range of traditional East Asian architecture, including Chinese, Korean and Japanese temples, palaces, houses, ceremonial gates, pagodas and pavilions, and (2) the construction of procedural 3D models of roofs and brackets with unprecedented realism.

Compared to existing systems, our system is particularly useful for two important purposes: (1) by setting the parameters, the artist can control the shape of the building, to design a building in any one of the many East Asian styles, and (2) by randomly setting different shape parameters, a program can efficiently create many different buildings to form an entire ancient city or town. By restricting the range of the parameters, the program can create a town with some specific characteristics, for example, a town built in southern Chinese style. By modifying procedures in the system, the program can also be extended to create buildings of new designs, and buildings with more details.

image of brackets and beams with Korean texture
image of Chinese-style hall with brackets image of Chinese-style palace
image of Chinese-style bridge image of Chinese pagoda

Procedural Modeling for Non-Formal Parks and Gardens

We have designed and built a system to automatically create the layout of a non-formal park. Although there are many modules in our system, the main contribution of our system is a novel bridge-finding algorithm. Other major contributions are the automatic generation of lakes and rivers, finding paths through the park, and an automatic process for creating a full layout for a Japanese-style garden, designating areas for pagoda, teahouse, moss garden, and dry garden.

 3D view of procedurally generated Japanese garden


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