MAP VOLUME TO SURFACE wb_command -volume-to-surface-mapping <volume> - the volume to map data from <surface> - the surface to map the data onto <metric-out> - output - the output metric file [-trilinear] - use trilinear volume interpolation [-enclosing] - use value of the enclosing voxel [-cubic] - use cubic splines [-ribbon-constrained] - use ribbon constrained mapping algorithm <inner-surf> - the inner surface of the ribbon <outer-surf> - the outer surface of the ribbon [-volume-roi] - use a volume roi <roi-volume> - the volume file [-voxel-subdiv] - voxel divisions while estimating voxel weights <subdiv-num> - number of subdivisions, default 3 [-output-weights] - write the voxel weights for a vertex to a volume file <vertex> - the vertex number to get the voxel weights for, 0-based <weights-out> - output - volume to write the weights to [-output-weights-text] - write the voxel weights for all vertices to a text file <text-out> - output - the output text filename [-myelin-style] - use the method from myelin mapping <ribbon-roi> - an roi volume of the cortical ribbon for this hemisphere <thickness> - a metric file of cortical thickness <sigma> - gaussian kernel in mm for weighting voxels within range [-subvol-select] - select a single subvolume to map <subvol> - the subvolume number or name You must specify exactly one mapping method. Enclosing voxel uses the value from the voxel the vertex lies inside, while trilinear does a 3D linear interpolation based on the voxels immediately on each side of the vertex's position. The ribbon mapping method constructs a polyhedron from the vertex's neighbors on each surface, and estimates the amount of this polyhedron's volume that falls inside any nearby voxels, to use as the weights for sampling. The volume ROI is useful to exclude partial volume effects of voxels the surfaces pass through, and will cause the mapping to ignore voxels that don't have a positive value in the mask. The subdivision number specifies how it approximates the amount of the volume the polyhedron intersects, by splitting each voxel into NxNxN pieces, and checking whether the center of each piece is inside the polyhedron. If you have very large voxels, consider increasing this if you get zeros in your output. The myelin style method uses part of the caret5 myelin mapping command to do the mapping: for each surface vertex, take all voxels closer than the thickness at the vertex that are within the ribbon ROI, and less than half the thickness value away from the vertex along the direction of the surface normal, and apply a gaussian kernel with the specified sigma to them to get the weights to use.