View Full Version : Smoothing Group

09-19-2001, 01:50 PM
Probably a Little OT, but what exactly is the smoothing group's function in a 3ds max object ?


09-19-2001, 04:24 PM
if u didnt have that all faces will be smoothed together giving a smooth appearance for everything but sometimes u want to certain creases not get smoothed out (ie give a sharp line between faces)
explained well, no!

09-20-2001, 09:31 AM
ya not bad!...
while modelling, you already tweak the model to get the sharp lines where you want. So, while importing i am getting the triangles, calculating my normals, setting up gourad shading and the lighting should do the rest. right ? . I don't get it. The What, Why and the How of smoothing. So, i get the face numbers of one smoothing group. what now, I average their normals ??


09-20-2001, 12:42 PM
You can calculate the right normals for each vertex in your model by using the following algorithm:

1. Calculate each normal per face
2. For each vertex in each triangle find all neighbour triangles that belong to the same smooth group, then average the sum of the normals of these triangles.

The result is that triangles in the same smoothgroup will be shaded, while triangles from different smoothgroups share a sharp edge.

Of course you can put lots of optimizations in step 2. (create as little vertices as possible etc.)