Calculate Boyer's (2008) relief index for a surface
A function that calculates relief index following Boyer (2008) Relief index of second mandibular molars is a correlate of diet among prosimian primates and other mammals. J Hum Evol 55:1118-1137 doi: 10.1016/j.jhevol.2008.08.002
RFI(plyFile, alpha = 0.01)
An object of classes 'mesh3d' and 'shape3d'
Step size for calculating the outline. See details
The function requires an object created by reading in a ply file utilizing either the read.ply or the read.AVIZO.ply function, with calculated normals.
Relief index is calculated by the ratio of three-dimensional surface area to two dimensional area on meshes that represent specimen surfaces and have already been pre-smoothed in a 3D data editing program. Alignment of the point cloud will have a large effect on patch orientation and must be done in a 3D data editing program or auto3dgm prior to creating and reading in the ply file. The mesh must be oriented such that the occlusal plane is parallel to the X- and Y-axes and perpendicular to the Z-axis.
Some files may fail with pancake[TempF,] : subscript out of bounds. In these files it may be necessary to increase the alpha value which is default set to 0.01. Increasing the alpha value can cause the RFI function to over-estimate the size of the footprint. Caution should be exercised when troubleshooting by adjusting alpha