Decimation Master Random Vertices

I’ve been noticing some errors in decimation and was curious if others have run into this as well. Currently using the latest build of 2021.6.4

A lot of my workflow revolves around utilizing polypaint for material selection later in the game pipeline, so I always have Use and Keep Polypaint turned on. All meshes are made water tight through dynamesh before ever using ZRemesher or poly painting.

I first noticed a strange behavior after running a decimation and hitting F to center the selected subtool into frame. The entire document would look as if it was empty though the tool was still active, no matter how many times I hit F, the tool would never occupy the document. I then turned off Edit mode and drew the tool back onto the document. Even after re-entering Edit mode and hitting F again, the entire tool would disappear.

Dynameshed Model:

Decimated Model: - everything looks okay, but hitting F removes the tool from the visible document and the tool itself must be redrawn onto the screen. Hitting F at anytime displays an empty document though the tool is still active.

I exported the mesh and opened in Maya. This is where I could actually see the issue. A single vertex was sent outside the mesh bounds by almost 3 Billion units. By selected the vertices of the main mesh and inverting the selection, I was able to find the vertex and move it back close to the mesh, but this does result in errors with the defined normals from decimation. and ultimately results in an error that has to be repaired after the baking process in the dev pipeline, which is less than ideal.

Imported Model: - notice the faces stretched by the exploded vertex

Component mode to find the elusive vertex: - camera clipping had to be set to 100000000.000 just to locate the vertex in the viewport

World Space Location of the exploded vertex - well outside any mesh bounds, close to 3 billion in the Y axis

Getting this error to reoccur is hit or miss. I’ve had it happen on three models that received decimation, and sometimes the vertices are closer to the model, but this has never happened to me before and I have been simply dealing with the issue as best I can to keep moving on the work at hand. The issue, however, never presented itself until these most recent updates with 2021.

Hi @Firebert,

so you think the frame (press f key) and the vertex that get off at billion units of his original position are linked ? ( mean both objects are so small that you can’t to see them on the canvas.)
But why when you press F a second time it would frame properly on the model and without to take in consideration the vertex which is off the true object space ?

Dynamesh is fine, but the issue seems to start after the decimation., did you tried to check mesh and fix mesh at different stages ( dynamesh, decimation) before exporting to maya ?

otherwise, and because you say it the third times it happens on a decimated model, if you can get in touch with the support center by starting a new conversation with the support team, to report the issue just copy what you have posted here, if you can join a zpr/ztl file after the decimation stage for more investigation that gonna be handful.

Hope it helps

Support ticket in with a wetransfer link to the file (ZTL was too big to attach). Thank you! @facelessmindz

Hi @Firebert

Be sure to check problem meshes in ZBrush for mesh integrity issues with Tool> Geometry> Mesh Integrity> Check mesh. Meshes with out of bounds verts or other issues can be identified and repaired there.

Thank you!