Use GLuint rather than size_t to represent OpenGL indices.

size_t size in byte is dependent on the machine architecture.
In contrast, the OpenGL indices must be 32bits.

Specifically size_t does not work on any 64bits machine.

simulation/include/pcl/simulation/model.h

@@ -58,7 +58,7 @@ namespace pcl
     };
 
     typedef std::vector<Vertex> Vertices;
-    typedef std::vector<size_t> Indices;
+    typedef std::vector<GLuint> Indices;
 
     class Model
     {