Three‐Dimensional Imaging, Modeling, and Analysis
Lawrence R. Griffing · 2023
Three-dimensional (3D) imaging, modeling, and analysis occur at all scales and resolving powers. To generate a series of 2D images for stacking in 3D, the images can come from the physical sections of sliced objects, or if the object is transparent or translucent, from optical sections or sections generated from multiple views with tomography. Structure-from-motion algorithms can create 3D objects from different 2D views. Structure-from-motion software produces digital 3D photogrammetry, the ability to measure 3D objects from photographs. MRI acquires lateral (x-y) information in Fourier space. Signals produced by the x- and y-dimension magnetic gradients are spatial frequencies. Surface rendering divides the volume up into cubic voxels and makes boundaries through the voxels if the values of voxel vertices in a certain region are below a designated threshold. This produces a surface of constant scalar value in a 3D field called an isosurface. These surfaces are polygons. They combine to make a polygon mesh.