Turbosmooth Strange shading issue in rendering and viewport-3ds Max

rajak1jai

Hi there, I am modeling a led tv in max. After unwrap i noticed a shading issue in some parts of model. This issue exist in my initial file too when i opened it. I really don't know how to fix it. I cleared all smoothing groups, xform reset, checked for problem of isolated verts, multiple edges, overlapping uvs/ geo face, and flipped normal, everything seems ok to me at geometry point. It shows black face, very thin edge when turbosmooth applied both in render and viewport and sometimes auto swap the black effect if tick explicit normal in turbosmooth but get that black area in renders. I searched for this issue and taken 2 days to solve, still cant find a solution. I applied the edit normal mod and unified all Normal,Face,Vertex and edges, it gives me some part rendering ok and some part have still weird shade. I edited those problematic edges increasing edge pinch that somehow solved a little but don't want to try this method. Its effect only noticeable in turbosmooth applied on geometry not the current working object. Sometimes it shows good in viewport but renders black patch on some parts if i apply meshsmooth. It will be great if someone can help me attached all files.

Jakro

I had a quick look and i believe it's just a matter of poor topology. I believe that the artefact is being caused by a triangle subdividing in a way that caused it to self shadow. I would try to use quads near these hols as they're more likely to divide nicely. I would suggest having a look around at how some other people have created holes in their meshes. This page can be translated quite easily with chrome and shows some examples of subdividing holes http://www.etereaestudios.com/training_img/subd_tips/agujeros.htm Though there's a lot more out there if you go looking. In some cased ngons will subdivide nicer than triangles so have a play around with your topology and find out what works best for you

cptSwing

Yup, try connecting the relevant vertices differently (trivial on a flat surface) and you should be good to go.

rajak1jai

Jakro i tried to pinch verts that fixed somehow those shading, is it really a bad topology? i modeled a test object, same topology this time it renders good. I am in trouble i have to fix model again unwrap again

Neox

You just have a pretty nasty quad there and as quads are always 2 triangles under the hood.
so there are 2 ways the interior edge can go


1. is your current status
2. is what the interior edge ideally would go
3. is what it is actually right now, causing the shading issues
4. would be, moving that bottom point to a position where both solutions would work fine

of course you could also triangulate it to be like 2. on a flat surface that is no problem.