title: Handling multiple Primitive items inside a glTF2 Mesh?
body: <p>I am developing a small app using OpenGL ES and the glTF reference loader library (c#) on a Xamarin Android based Visual Studio project.</p>
  
  <p>Right now, I am trying to build my own class structure for organizing the models' data. I read the specs, and the skinning tutorial was very helpful, but now I have a question concerning the meshes and skins array:</p>
  
  <p><strong>Question:</strong></p>
  
  <p>This is an excerpt of the model's Skin section:</p>
  
  <pre><code>"skins" : [
      {
          "inverseBindMatrices" : 115,
          "joints" : [
              6,
              7,
              8,
              9,
              10,
              11,
              12,
              13,
              14,
              15,
              16,
              17,
              18,
              19,
              20,
              21,
              22,
              23,
              24,
              25,
              26,
              27,
              28,
              29,
              30,
              31,
              32,
              33,
              34,
              35,
              36,
              37,
              38,
              39,
              40,
              41,
              42,
              43,
              44,
              45,
              46
          ],
          "skeleton" : 0
      },
  </code></pre>
  
  <p>The whole model has 5 Meshes (with multiple Primitives) and several bones/joints. However the <strong>item count</strong> of Skins in the glTF file is way higher than 5! How can this be?! I thought that for each Mesh that is controlled by an armature, there is a Skin? Why are there so many more than 5? Is it because of the multiple primitives? But why are there so many inverseBindMatrices?</p>
  
  <p>It seems to me that there are many pitfalls for a newbie like me. The tutorials are a good starting point, but the examples shown there are so minimalistic, that everything is easy. However, real world models taken from any website are far more complicated than this.</p>
  
  <p>Maybe someone can help me out?</p>
  
  <p>P.S.:
  The model I talk about can be found at
  <a href="https://www.dropbox.com/s/jc7k7jcipihbl5c/littlegirl.gltf?dl=0" rel="nofollow noreferrer">Dropbox link to glTF file</a></p>