Hi, I'm creating a small soft with OpenGL but when I load a 3DS model it looks like faceted ! There is no smoothing between the faces. I use Gl.glShadeModel(Gl.GL_SMOOTH); but it change nothing ! Here is a picture : http://picasaweb.google.com/viewon01/OpenGL#5380203925050881714 Here, you can download the Smurf model : http://www.3dvalley.com/3d-models/characters Do you have an idea ? Here is the way I create the normals : Vector3[] sum = new Vector3[Vertexes.Count]; for (int jj = 0; jj < TrianglesIndices.Count / 3; jj++) { int indice1 = TrianglesIndices[jj * 3]; int indice2 = TrianglesIndices[jj * 3 + 1]; int indice3 = TrianglesIndices[jj * 3 + 2]; Vector3 v1 = Vertexes[indice1]; Vector3 v2 = Vertexes[indice2]; Vector3 v3 = Vertexes[indice3]; // Calculate the surface normal Vector3 e1 = Vertexes[indice1] - Vertexes[indice2]; Vector3 e2 = Vertexes[indice2] - Vertexes[indice3]; Vector3 surfaceNormal = e1.Cross(e2); // Sum it at the vertex index sum[indice1] += surfaceNormal; sum[indice2] += surfaceNormal; sum[indice3] += surfaceNormal; } for (int index = 0; index < Vertexes.Count; index++) { sum[index].Normalize(); Normals.Add(sum[index]); }

Thanks,

I don't understand, I have a per-vertex normal.

I calculate the surface normal for each vertex, BUT I sum it...

at the end I normalize it, so every normal is different. Right ?

Vertex normals are averaged, not just summed.

I understand the need to normalize them after averaging. This is the first time I've heard that they can be summed with the same effect. I stand corrected.

Thanks for your answers,

Can you tell me where I'm assigning normals to incorrect vertices ?

I don't understand where I have do an error !

Thanks

One idea: your vertices aren't shared, I mean, all triangles have 3 vertices, which are not shared with the other, neighboring triangles, although they seem to be the same verices.
How many polygons/vertices you have?
If vertices=3*polygons, your vertices aren't shared, so you cannot calculate average that way.

I hope it made sense, or I didn't misunderstand something, or not giving dumb advice.

Thanks,

It is an idea, in fact I read a 3DS file... so I have supposed they are correctly organized !

But maybe you're right !
I have :
- 32168 vertices !
- 21440 triangle (with 3 indices for each)

So, how can I reorganize my vertices... it sounds a complex task to keep good performance!