You'll loose information when converting to polypaint if the vertices aren't there to support all of it. If you combine zapplink with the texture and projection master, any changes get converted to the texture itself (so the sharpness should depend more on the texture resolution and the amount of document pixols)
LUMPY BOULDERRRRRRS! Looks pretty good, that water could do with a more vertical texture though :) Will there be some kind of path to walk through or is this a flyaround kinda thing? Are there normal maps on those rocks? It looks pretty flat, maybe it's the light? Looking forward to updates!
the holes in your mesh look like you haven't welded your vertices at that position or you have a hole in your mesh. happens sometimes when you cut polygons. post a picture of your base mesh and triangulate before, then it should be easy to see.
Zbrush's polypaint is also painting vertices, so if you have a low-poly mesh you won't be able to paint at any resolution you choose. Substance Painter paints textures so you can do any size you want/need.
Try adding some vertical edges that line up roughly with the centre of each of those top details (you can remove them later). This video explains the issue, even if its not the issue its good to know :) https://www.youtube.com/watch?v=USGFRzQWxdI
Try straightening the UV's on either side, so that they line up vertically. The issue isn't being helped by the UV's on the left, being at a different angle from those on the right (at the seam basically). Also adding a detail normal map can help to ease the problem.
How do these extra colors show up? You bake lighting to the vertices via the VertexPaint Radiosity settings; and then the result is added to the mesh as several datasets in Channel Info? (Just interested because this seems bizarre to me and I'm not sitting in front Max this week ;) )
Looks like a great start, the proportions are looking okay, try and get the same atmosphere without paying too much attention to how accurate the vertices are placed. You have a good perception of the 3D elements I'd disregard the bike and just continue on the environment.
Set a hokey or menu item to "Select Vertices By Bone (Skin)". I have a script called Replace Weights. It takes all the vertex influence from one bone and assigns them to your target bone. I can package it up if you are interested.
Awesome thanks for the solution. I didn't have your exact issue (my viewport looked like there was massive z fighting everywhere as well as weird white artifacting near the vertices). Changing my near clip plane to 1 or above fixed the issue.