Finely detailed landscape detail layered over topographic heightfield.
In a number of projects, Situ has been faced with the problem of layering one type of 3-dimensional information onto another. In its simplest form, the problem has been to apply a finely detailed 3D texture geometry onto a terrain model in order to represent vegetation or some other landscape feature.
Detail, Frank Lloyd Wright: From Within Outward, Taleisin Project, MoMA 2007
This is commonly accomplished for rendering purposes using bump mapping, although this results in graphical representations of 3D surface texture, Situ's focus has generally been to develop and apply such techniques for fabrication. The attached images document a process developed to accomplish a carefully calibrated modulation of the surface through a process of layering height fields.
A heightfield, or texture map, is an image that defines spatial information in terms of color value which can be correlated to a range of spatial displacement along a depth axis. In a black-white gradient, black corresponds to zero displacement and white to maximum displacement. Other gradients such as hue or RGB can be used to define further transformations. Working with images is thus a quick way to generate 3D textures, and by overlaying and manipulating multiple images, surfaces with two or more degrees of modulation can be generated. For example, a topographic heightfield can be layered with other gradient images to create finer modulations within a larger landscape, see below.
Heightfields for Frank Lloyd Wright: From Within Outward, Taleisin Project
For two values to be combined they must be in the same dimension. For an image to be applied to a surface, both the surface and the image must be able to match up. Such was the case for Situ's From Within Outward project - a fabrication exercise in recreating the landscape, down to the articluation of crop configurations, of Frank Lloyd Wright's Taliesin East project. The studio began by studying aerial photographs that document the state of Taliesin East in 1959 at the time of Wright's death. Using these photographs, Situ was able recreate map speficic landscape features, seen below, onto a digital elevation model representing the larger elevational conditions of the site. The final model of which is shown in detail at the top of this page.
Top: Four intensity fields for the Taleisin Project. Bottom (left): Aerial photograph of Taleisin plot, 1955. Right: Aerial photograph of Spring Green, 1937
In another case, the village of P'sagot - the subject of Situ's Ungrounding project, was subject to a similar transformation; however intensity fields were allowed to grow and decay naturally with the aid of a computer script as opposed to human intervention. The images below depict the fine details on a CNC milled physical model of the site.
Detail of CNC milled model for Ungrounding