I am using Polypaint by Polygroup.
I am getting jaggy, distorted edges and some kind of bleeding between the edges and colors. The mesh is already pretty dens.
Is there any settings or features, I could control the blurriness or the sharpness of the edges when using the operation Polypaint by Polygroup?
Anything else I am missing?
Thx for any little help, appreciate it!
cheers
Hello @FattyBull ,
Much as I explained in your previous thread on masking, polypaint, masking, and polygroups are all highly dependent on the quality of the topology. To get the cleanest results, your topology either needs to be very high resolution (higher than this mesh), or your topology has to be drawn in such a way so that it forms a clean border.
Keep in mind also that polypaint is vertex paint. The color is assigned to a point on the mesh, not to the actual polygon. If points on opposite sides of the polygon have different colors assigned to them, there will be a short transition there between the two colors. If the polygon those mixed points are assigned to is stretched and distorted, or non-square shape, this will cause a jagged bleed in the shape of that topology. A higher resolution mesh will hide this bleed better by virtue of the small size of the polygons. It will be much more apparent on a lower res mesh with much larger polygons.
In the following scenario, you see I have a clean looking polypaint on a fairly low res mesh. This is because the points that I have poly-painted all fall along one edge that forms a clean border with another polygroup. There are polygons that blue-painted verts on one side, and green-painted verts on another, resulting in a short transition between the two colors. Because these polygons are fairly well shaped quads and form a clean edge, the transition is barely perceptible. On either side of that border there are polygons that are not as well-shaped, but they play no role in defining the border.
However, if I change the polygrouping so the green area becomes one loop of polygons larger, now the transition area involves those unevenly shaped polygons, resulting in a jagged edge “bleed” like you have in your example. To correct this I would either need to clean up that topology so the polygons are all better shaped, limit my polypaint to polygons that have clean edge borders, or increase the resolution of the mesh to a degree where the polygons are so small, this bleed is no longer easily seen with the naked eye.
Polypaint performs best on a mesh with evenly distributed quads as close to square shaped as possible. Painting over triangular geometry will create jagged edges, and this effect will be more pronounced the lower res your geometry is.
In some situations, ZRemesher can be used with the “Keep Groups” option to quickly redraw your topology in a more polypaint friendly fashion:
Good luck! 
yeah, that all makes sense. Thank you very much for all your efforts and this great explanation.
The weird thing is, that I created a nice topology by using Edge Loops, Group Loops and Panel Loops.
But yes, when using the knife brush for example, the operation creates a ton of triangles on the edges.
And those edges (or triangles) create that bleeding. Even if I increase the resolution, this is not going to work well.
I guess the solution is to Zremesh the whole thing, making sure the final topo supports the vertex color information.
I guess that’s what needs to be done before the poly painting, right?
Or am I missing something here?
thanks a lot, appreciate it and keep rocking,
cheers
It’s nice in parts, but it comes at the expense of some awkward connections from the old topology to the topology that was newly drawn by the function. If you add another loop or two, this may give you the additional edge loop you need there to ensure a clean border.
Many tools that are designed for shaping form in the program will do this. These are tools that work at a single level of resolution, and quickly reshape the mesh. For some output needs, this is sufficient. For instance, a mesh destined for print doesn’t need to worry overmuch about the topology on the mesh. In many cases, you can simply Decimate that out and print without issue.
However, more advanced needs like polypainting, posing, UV unwrapping, and texture creation and export require more specialized topology. If working towards those goals, at some point you need to transition to a multi-resolution mesh with a clean base level topology and multiple levels of subdivision to get the best results. It is therefore useful to approach most projects with both a “shaping” phase where you quickly establish the form, using ZBrush resurfacing tools like Dynamesh and ZRemesher to clean the mesh as you work, and then transition to a multi-res tool with higher quality topology for the purposes listed above.
Don’t be so sure. Pumping up the resolution on sub-optimal topology is a “brute force” solution, but it can definitely work if you increase the resolution high enough. In the following image I have a Decimated sphere which is sub-optimal topology for polypaint, containing mostly triangles and poles, and far too low resolution to produce good results even if the topology was better. At 40 million points on the same mesh this produces perfectly smooth results to the naked eye. However, it would still be more efficient to have well-drawn topology for this purpose in the first place. This sort of topology will be very difficult to work with for the purpose of creating and exporting textures.
