avoiding sharp edges in game model

hegvbwkeuyrv

what are some good ways to avoid "perfect clean edges" in game model? while saving polycount of course. I saw some marmoset viewer, and some just have clean sharp topology, but it has a jaggy deformed line in their beauty shot. Any idea how to achieve that quality?

Eric Chadwick

An image of what you're talking about would help. Draw an arrow pointing at the effect, to make it clear.

Axi5

Sounds like a few things.

Firstly, the only way to reduce the sharpness of curvature in game models is to add more geometry.

Secondly, the art you could be talking about where it's clean in one picture but jaggy in another picture could be using a tessellation shader which increases the geometry as you get closer.

Or I could be misunderstanding your question, so please refer to Eric's post.

hegvbwkeuyrv

https://www.artstation.com/artwork/EDW0q its this one, the boots, especially the heel

CarlCraft

I'm not sure what you are talking about, I don't really see any jagged lines... Or am I looking at the wrong part?

hegvbwkeuyrv

this one. The topo is straight, but the beaty is jagged (in a good way)

hegvbwkeuyrv

this image

hegvbwkeuyrv

i cant seem to uopload the image, sorry. its the heel, near the middle where it bends 90 degree near the belt

Dash-POWER

He probably means the top part of the boots are too lowpoly, specially edges of the cloth. This could be fixed by increasing geometry or applying tessellation shader how @Axi5 mentioned. But for me it looks ok.



Another trick is to change topology of your geometry and increase vertices where it is necessary.

huffer

I think he's saying how even though the metal edge of the heel cutout only has one edge, it's still soft - it's because of normal map baking - the high poly model used as source for the bake was soft and this information is transferred, even though the low poly only has an edge there.

hegvbwkeuyrv

@huffer yeah! that's what i meant! So i just need to retopo my already soft edge high poly, bake it in substance painter, and all is good?

@Dash-POWER that is some good tips can you explain a little bit about tessellation shader tho? I'm quiet curious about it.

Dash-POWER

Tessellation shader increasing number of vertices. Geometry shader on a GPU is responsible for that. It's commonly use in games for increasing details on more visible surfaces such as character faces, terrains etc. You can read more on the Polycount wiki about this technique or regular wiki

Axi5

Dash-POWER said:

Tessellation shader increasing number of vertices. Geometry shader on a GPU is responsible for that. It's commonly use in games for increasing details on more visible surfaces such as character faces, terrains etc. You can read more on the Polycount wiki about this technique or regular wiki

Not quite. The Geometry shader isn't supposed to handle tessellation, though it can do it, it's performance would suffer. The specific shader is actually called a tessellation shader. 

Geometry shader is useful for creating or discarding geometry such as doing line trails etc. 

hegvbwkeuyrv

do marmoset support tesselation shader?

Axi5

Yup
https://www.marmoset.co/toolbag/

Under the Features tab and Material section


The model you're discussing doesn't use tessellation though, just a normal map

Dash-POWER

@Axi5 Ah, thanks for correction. I thought it was Geometry.

hegvbwkeuyrv

@Axi5 wow man why didn't i know that. So lets say i want to make a CAVE with really nice background cave walls. I already make the cool procedural textures in substance designer. Then what i need to do is just make a deformed plane following the outline of the cave, and apply that material in marmoset? 

xaled

Or can be achieved with "smoothing groups" when no higher poly model is available