code: private static RectBounds fillVertexBuffer(
              ElementReader reader,
              FloatBuffer vertexBuffer) throws IOException {
  
          // Just go though the vertices and store the coordinates in the buffer.
          Element vertex = reader.readElement();
          RectBounds bounds = new RectBounds();
          while (vertex != null) {
              double x = vertex.getDouble("x");
              double y = vertex.getDouble("y");
              double z = vertex.getDouble("z");
              double nx = vertex.getDouble("nx");
              double ny = vertex.getDouble("ny");
              double nz = vertex.getDouble("nz");
              vertexBuffer.put((float) x);
              vertexBuffer.put((float) y);
              vertexBuffer.put((float) z);
              vertexBuffer.put((float) nx);
              vertexBuffer.put((float) ny);
              vertexBuffer.put((float) nz);
              bounds.addPoint(x, y, z);
              vertex = reader.readElement();
          }
          return bounds;
      }
docs: Fill the vertex buffer with the data from the PLY file.