   3ds loader .. calc normals with multiple vertices used?!
  hii got an loader for 3ds files in openGLan it works nearly perfect, ok ,thereare no NORMAL's saved in 3ds file formati GOOGELD a lot of things with"+opengl +calculating +normals etcand i found some examples of calculatin face normal,ok,but there is &#111;ne mistake in itwhen calculatin round objects like treethere are points that should have a normaldirection mixed because that point is usedby some faces (sorry for my english,i normally speak &#111;nly german)  for example this are 8 faces and 8 points (watching from top)  <img src="http://img111.imageshack.us/img111/4395/normal3df.jpg" alt="problem" /> when calculating  point '0' with '2' and '3' they miss '6' and '7'normally the normal of 0 must look North and not northeast likeherewhat formula is there to combine all vertices that are mutiple used by faces(please no google answers anymore)
  First off: 3ds files do support normals.Second: Learn to use google. :DIf you want to calculate the "average" normal for those points..1) calculate the normals of ALL faces that is connected to one vertex. (simple cross-product..)2) Average those (should be depending on the area of the face) and you have your normal.For a cube, you normally want "hard" edges, that is, no shared normals, but to use the face-normals instead, which means you have to split each vertex into 3 vertcies...Good luck!;chunk 0x4110  == verticeschunk 0x4120  == face polyschunk 0x4140:  == texture coordinatesetc..etcgoogle tell not about the mistery what chunkuses/stores normals but it looks thatYOU "gugli" know more about it :)please feel free to tell us more about it hereor did anybody else know a complete serious describtion of .3ds fileswith "normal" definitions inside..so i can stop thinking about normalswhen using 3d editors (only watching face orientation when creating objects)a lot of "google" result tells that 3ds did NOT store normals  ;  set the normal for the vertex to be the average face normal for all the triangles that use the vertex.  this will look "right" and will provide smoother shading than having the vertex have a different normal for each triangle that uses it.for ( each vertex ){    find all the triangles that use it;    for (each triangle)    {   add the tri normal to the average;    }    normalize the average;}-me   ;Quote:Original post by Palidineset the normal for the vertex to be the average face normal for all the triangles that use the vertex.  this will look "right" and will provide smoother shading than having the vertex have a different normal for each triangle that uses it.for ( each vertex ){    find all the triangles that use it;    for (each triangle)    {   add the tri normal to the average;    }    normalize the average;}-meAgree. In addition, I've just written a basic 3ds loader (tell me if you want the source to look at, and I could mail it to you, if you're interested) and AFAIK there are no normals stored in the 3ds format file. Most of the others formats I looked at don't keep normals simply because they can be calculated from vertices. Only a couple of formats do that (but I don't remember wich).