[A]nisochromatic Meshing

This implementation is based on the logic described in this algorithm [https://grgrdvrt.com/works/contour-lines/] for contour lines based on noise, in our case is from a color data mesh. I initially fell inlove with the iso-contouring by playing w/ ZBrush polygrouping & group loops functions. They produce extremely intricate groupings of meshes based on color thresholds as seen below. Obviously Z-Brush’s meshing capabilities are unmatched however I always wanted to attempt to generate a process that was similar.

ALGORITHM –

As described in the Grgrdvrt post the typical way to achieve a process like this is implementing a marching cubes algorithm, however

Groupings = Since we are interested in multiple iso-values at the same time (driven by the number of groupings the user wants) a better solution was needed in order to be able to create the mesh groupings that can near mirror the ZBrush groupings by polypaint. So instead of computing one iso-value per face, we will compute all the iso-values per face, add them to a list, create the winding, create a mesh and append it to the mesh created for each group. This will give us a continuous mesh loop around the entire global mesh, with each group containing a unique color.

.EXAMPLE BELOW = This example is looking at simply 2 groups, Group 1 w. values between 0.0 – 0.5 and Group 2 w. values between 0.5 – 1.0. The Yellow represents topological face edge index, White represents topological face vertex index and the Red represents vertex color data.

.DATA STRUCTURES = Left image is raw mesh w. color data vs Remesh based on iso contour values
.EXAMPLE GROUPING SIZE  = Same underlying data structure w/ Group Size of 2 vs Group Size of 32

MESHING BY TRAILS & BY POSITION Output changes dramatically when we switch how we want to generate the meshing process, below we see both by agent trails and by agent positions.

THESHOLD ADJUSTMENTS: We can also begin to get very interesting effects by varying the threshold values as well as the underlying mesh density

ZBRUSH EXAMPLE: As I mentioned earlier ZBrush was a huge inspiration for this process. Below we can see the grouping methods from ZBrush and the output loops

MESHING BASED ON CULEBRA AGENT POSITION INSTEAD OF TRAILS –