Dynamesh giving me extremely faceted/strange results

guitarguy00

Hey guys, I took a High Poly mesh out of 3DS max into Zbrush to do some manual cuts/boolean operations and noticed when I performed a Dynamesh operation, it gave me faceting. This is even after subdividing multiple times, increasing the size of the mesh and putting in a high resolution for the Dynamesh. 

This is the High Poly out of Zbrush after Dynamesh and shown in Toolbag, you can see the faceting :



I then tried simple objects like a cylinder and received a distorted reflection effect post-dynamesh. The post Dynamesh model is on the left, the base HP out of 3DS on the right.



Any ideas as to why this may be? 

SuperFranky

1. Normal subdivision surface from Maya as HP

2. Dynamesh as HP
here i exported a cylinder smoothed to 3 levels and dynameshed to 1m polys




You can clearly see the lines that dynamesh gives you. Basically what you see in Zbrush's viewport is what you get when you bake. To avoid this the mesh you're Dynameshing has to have more polys before you dynamesh.
Here i exported a cylinder smoothed by 5 levels and dynameshed it to 1m polys.

Noors

This is because dynamesh is like subdividing without smoothing. By adding points on flat faces, you basically "break" the smooth interpolation between normals, which ironically looks worse than the less defined mesh.

To get what happens, you can create a low poly cylinder in max, and add a tesselate modifier (edge, tension 0, iteration 3...). The angles are more visible.

So, either you add more subdivs to begin with, or you use polish in zbrush to relax the vertices a bit. Keep in mind that metallic 100% smooth is the most hardcore to see artefacts. So you may also want to check with a material approaching the final look, with the object at the right distance, with the maps at the right resolution, etc...I mean it may be totally not noticeable.

guitarguy00

Noors said:

This is because dynamesh is like subdividing without smoothing. By adding points on flat faces, you basically "break" the smooth interpolation between normals, which ironically looks worse than the less defined mesh.

To get what happens, you can create a low poly cylinder in max, and add a tesselate modifier (edge, tension 0, iteration 3...). The angles are more visible.

So, either you add more subdivs to begin with, or you use polish in zbrush to relax the vertices a bit. Keep in mind that metallic 100% smooth is the most hardcore to see artefacts. So you may also want to check with a material approaching the final look, with the object at the right distance, with the maps at the right resolution, etc...I mean it may be totally not noticeable.

Thanks for the information, really insightful. I managed to fix the faceting issue with the handle by using 2 more iterations of subdivision before dynamesh. I turned on 'Facet' mode in 3DS to see what the handle actually looked like without any smoothing(was exactly as it was displayed in Zbrush) so more Subdivision was needed as you said.  Still some slight dithering as seen with the two cylinders but as you said, that is with extreme gloss value, metalness and up close. 

I always turn on maximum metalness and gloss so I can inspect under heavy scrutiny. It is part of my perfectionism/OCD haha. No material of mine will ever be that glossy/metallic unless I am sculpting the T1000 

guitarguy00

SuperFranky said:

1. Normal subdivision surface from Maya as HP

2. Dynamesh as HP
here i exported a cylinder smoothed to 3 levels and dynameshed to 1m polys




You can clearly see the lines that dynamesh gives you. Basically what you see in Zbrush's viewport is what you get when you bake. To avoid this the mesh you're Dynameshing has to have more polys before you dynamesh.
Here i exported a cylinder smoothed by 5 levels and dynameshed it to 1m polys.

Thanks heaps for the information and pictures. I would have thought 3 iterations of Subdivision would be enough but didn't know about Zbrush not using any smoothing at all. Thanks again.

guitarguy00

Nice and smooth now