About a week ago I watched a video that claimed that smoothing groups used in Maya reduce the amount of actual vertexes rendered but is not shown in the vertex count. He further stated that the way smoothing works is by taking verticies that are close by and merged and averaged them. This causes the real-time performance of the mesh to be slightly higher. Is this also true for Blender? In my case I would be experting the model as fbx to be used in Unreal.
Smooth shading has no effect on the object geometry or polygon count, it’s just a visual trick
actually the OP is correct its explained here if your interested.
What the person in the tutorial was probably talking about was using per-face normals to add sharp edges, instead of splitting vertices. You can do this with Blender using the “auto-smooth” function.
Fun fact: in some game engines, you don’t actually get the reduction in vertex count, because the GPU tries to render the smoothing groups by splitting them into separate verts!
Smoothing groups / hard edges are just a level of abstraction that makes the mesh easier to work with, the vertex’s are split when they go to your card to be drawn.
Smoothing groups / hard edges are just a level of abstraction that makes the mesh easier to work with, the vertex’s are split when they go to your card to be drawn. Using hard edges has an added cost to your vertex count in VRAM. It’s nearly as much as a single faceted bevel. This is why you see them used more these days to reduce shading artifacts over smoothing groups for normal mapped models (as you also need to split the uv and add a bleed area to stop the normals being interpolated in the normal map)