3-dimensional objects

Adam B. Smith

2025-04-25

fasterRaster has limited support for 3-dimensional GRasters and GVectors. A GRaster is like a multi-layered raster, except that layers contain values in “voxels” (3-dimensional pixels), where each layer has a z-resolution, in addition to its normal x- and y-resolutions. These layers are called “depths”. A 3-dimensional vector has a z-dimension, so any point (i.e., an actual point, or points that together define a line or polygon) has a third dimension. You can test if an object is 3-dimensional using topology(), is.2d(), or is.3d(), or by looking at its metadata (i.e., just enter the name of the object in R and look at what is displayed).

Thus far, no functions that handle 3-dimensional GRasters or GVectors have been tested. Some functions like spatSample() have arguments that allow you to do something with a z-component. Also, some of the “getter” functions can report information about the third dimension of a GRaster or GVector.

Three-dimensional GRasters and GVectors should (?… remember, no testing yet!) work with most functions. In some cases, the third dimension will be ignored or removed. You should get a warning in these cases.