Im new to zbrush, im trying to remesh this model to make an LP model. Im using zremesher and ive made some poly groups but zbrush isnt calulcating the corners very well. Does anyone have some advice? Ive attacched images of the high poly vs the LP remesh.
Also, the LP is at 35,000 verts so i dont think its a resolution issue.
Hi @Peter_Randall ,
When you go from a high poly model to a low poly model, remember that form and detail will be lost as you eliminate points from the surface. It will be necessary to subdivide the low poly model and project the detail from the original onto it in order to reclaim it. In order for a low poly mesh to keep its edges crisp when being subdivided, it requires precisely drawn edges and for those edges to be creased.
For complicated hard surface models, no auto-retopo solution can identify and draw edges the way a human could. There is no magic button for this. You will need to instruct ZRemesher on which edges you would like to keep, and in some situations it will be necessary to manually retopologize or touch up problem areas.
For simpler forms with simple planar surfaces, sometimes just enabling “Detect Edges” will be enough, and ZRemesher will correctly identify which edges to draw. For more complicated forms or ones that also involve sections of curved surfaces, it will be necessary to provide ZRemesher with cues to which edges need drawn.
The option that provides you with the most control while doing this is the “Keep Polygroups” option. If every surface that is to have a hard edge between it and another section is assigned a different polygroup, ZRemesher will draw creasable edges exactly along those polygroup borders. One of the reasons this situation is not giving you the results you want is because the bottom of the inset area is a different polygroup, but the planes of the sides are not. You would need to make certain that each side of the inset area is also a separate polygroup in order for the feature to find your corners there and keep them crisp.
However, I will warn you that a very shallow inset area like this is going to be a very ambitious bit of geometry to try and keep through a ZRemesher process. ZRemesher is better used for developing the major forms and edges, but will struggle to draw detail that fine and shallow.
This means that just like in most other cases, it is better to work towards fine detail in the end stages of your model after clearly defining the major forms. If you are attempting to end up with a piece of low poly topology with precisely creased edges, then this sort of detail is better modeled in after you have stable low poly topology for the major forms that you don’t expect to have to change again. If you are working towards a high resolution model it would be better to create that sort of detail as fine surface detail for an eventual normal or displacement map, or stamped in at high poly and then decimated for print output.
Good luck!