Problem with Vertex Normals ?

Peksio · Oct 2016

Hello. I would like to ask You for Your help. I have problem with Vertex Normals, or at least I think that this is my problem ^^

I have low poly model. And this model looks weird. Normal map is sometimes fixing it and sometimes not. I would like to know how I can avoid it. How can I fix it ?

I know that my geometry is well ... not good looking. I also know that I can fix those bugs by adding geometry but I am kinda lost. I mean this is low poly so I wanted to get as low polycount as I could. How should I add geometry ? Or maybe there is some other way ?

Image: https://us.v-cdn.net/5021068/uploads/editor/t5/q2naidhpdhm9.jpg

Image: https://us.v-cdn.net/5021068/uploads/editor/qv/8k6ae8je5fca.jpg

Thanks and Cheers !

Eric Chadwick · Oct 2016

What is the context here? What kind of overall object is this? You probably don't need to merge the handle into the surface. This is creating a lot of extra vertices, and is pinching the surface. You can just float the end of the handle above a simpler surface. Same with the end of the trim at bottom left. The trim can just float over the surface.

These shading errors are caused by the vertex normals. Might help to read up on them.
http://wiki.polycount.com/wiki/VertexNormal

Peksio · Oct 2016

Thank You for Your answer. I know that I don't need to merge in this handle but I wanted more smooth and nicer slide of normal map.

I read a little about vertex normals and I think that now I have a small grasp of it. I will check these scripts for Maya tomorrow but what can I do if these scripts won't help me ? Should I somehow change my geometry ?

Eric Chadwick · Oct 2016

Yes, you should change the geometry. Detach the tube from the flat surface, and simplify the flat surface.

Peksio · Oct 2016

I understand. I assume that If I would like to keep that tube the way it is I would have to add a whole bunch of edge loops ?

Eric Chadwick · Oct 2016

It would depend on many things. How close does the player ever get to this model? What angle do they view it from? What real-world object is this based on and what does it look like in this particular area? Are you using a synched-normals rendering workflow?

Peksio · Oct 2016

It is important model, player will get a good look at it from various angles. I don't know exactly what is "synhed-normals rendering workflow". I googled it and I found out that this refers to special presets in baking soft (?). I am using Substance Painter. I found some information that Substance is using same algorithms for baking normals maps as UE4 needs which is good I suppose ?

But the truth is that these kind of bugs are looking good in vieport in Substance but they look horrible in UE4.

I am propably missing something here but I don't know what :P

Eric Chadwick · Oct 2016

Lots of info here.
http://wiki.polycount.com/wiki/Texture_Baking

gnoop · Oct 2016

It also depends on how polished the surface is going to be . Those shading gradients/artifacts could be compensated by synched normal map , not 100% perfect although. So if it's dirty or rusty surface with a lot of small bumps /normal map noise , it may be ok . If it's shiny metallic surface even synced normal maps would give you compression artifacts and highlight errors in actual game.

Instead of making edge loops or hard/splitted edges you could just rotate vertex normals themselves to be perfectly perpendicular to main surface. It would transfer shading gradients into less important areas.

Problem with Vertex Normals ?

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