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I have a sample model of a cube and a buddha downloaded from internet in 3ds format which I can load correctly into my program and view them without problem, but wanted to try and create my own model.

I created a simple box mesh in 3ds max, and exported it as .3ds (Converted to mesh -> export as .3ds)
When inspecting the .3ds file with a hex viewer, I was expecting to see 8 vertexes and 12 faces declared (as the model I downloaded from internet). But what i found was that it listed 26 vertexes, and 12 faces! And when I try to load that file with my .3ds viewer, my parser isn't detecting the face block (0x4120), which is strange because it worked for other objects downloaded from internet.

Do I have to set any special property in order to export a 3ds file with minimum vertexes and a vertex-index list?

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If your cube has hard normals, then each of the 8 vertices will need to be repeated 3 times because it occurs with 3 different normals, one for each cube face that shares it. That's 24 verts. You said 26, and I don't know where the other two come from, but if there are UVs on the model as well, perhaps some UV seam is causing that.

To export with a minimum number of vertices, you probably have to delete all UVs and smooth all normals, or some such. I don't know exactly how to do that in 3DS Max, but it should be possible.

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  • \$\begingroup\$ What do you mean by hard normals? \$\endgroup\$
    – Juan Pablo
    Jun 10, 2012 at 6:00
  • \$\begingroup\$ He means that each face has its own normals, the edges of the cube will have hard corners and all the vertices are duplicated. This is the usual way cubes are made, with hard edges and duplicated vertices for the normals. You can try stripping the UV info like Nathan says, then selecting all the vertices and putting them all in one smoothing group. In real work models are a combination of hard and soft edges controlled by smoothing groups, at least the last time I was mucking about in that part of the content pipeline. \$\endgroup\$ Jun 10, 2012 at 6:24

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