Create another vertex buffer

Question

Hi, I have a problem with AGAL. If I create another vertex buffer, like this:
_vertexBuffer = _context.createVertexBuffer(_cubeVertexes.length / 6, 6);
_vertexBuffer.uploadFromVector(_cubeVertexes, 0, _cubeVertexes.length / 6);
_context.setVertexBufferAt(0, _vertexBuffer, 0, Context3DVertexBufferFormat.FLOAT_3);
_context.setVertexBufferAt(1, _vertexBuffer, 3, Context3DVertexBufferFormat.FLOAT_3);
_vertexBuffer2 = _context.createVertexBuffer(_cubeVertexes2.length / 6, 6);
_vertexBuffer2.uploadFromVector(_cubeVertexes2, 0, _cubeVertexes.length / 6);
_context.setVertexBufferAt(2, _vertexBuffer2, 0, Context3DVertexBufferFormat.FLOAT_3);
_context.setVertexBufferAt(3, _vertexBuffer2, 3, Context3DVertexBufferFormat.FLOAT_3);
_indexBuffer = _context.createIndexBuffer(_cubeIndexes.length);
_indexBuffer.uploadFromVector(_cubeIndexes, 0, _cubeIndexes.length);
_indexBuffer2 = _context.createIndexBuffer(_cubeIndexes2.length);
_indexBuffer2.uploadFromVector(_cubeIndexes2, 1, _cubeIndexes2.length);
and set the shader as follows:
protected var _vertexShader:String = [
      "m44 op, va0, vc0",  // multiply vertex by modelViewProjection
      "mov v0, va1",        // copy the vertex color
     "m44 op, va2, vc1",
      "mov v1, va3"   
    ].join("\n");
    protected var _fragmentShader:String = [
      "mov oc, v0",  // output the fragment color
      "mov oc, v1"
    ].join("\n");
the programme just display one vertex buffer's data on the screen. So I'm wondering how can I set the shader to display both vextex buffer's data?
Many thanks!!!

Answer 1

i am not sure about that (havent run any experiments) but i doubt the penalty will be that huge! Here is what happens when you call drawTriangles :
There are 2 buffers front and back buffer when you make a call to the drawtriangles function it draws the triangles to the back buffer (so you could call it repeatedly in a loop to draw multiple 3d objects, correctly sorted, thanks to z buffering) and the moment you call the present() function it swaps the back buffer (the one the draw triangles function drew triangles too) with the front buffer (which was being displayed to the viewer while the drawtriangles function was drawing triangles to the back buffer) so now you would be viewing the back buffer while the front buffer will be used by draw triangles function in the next iteration to draw triangles too (a pretty old technique,  but a very effective one (its used in opengl, i think its glutswapbuffers or something in gl, i have done demo with quite a lot 3d objects (primitives but heavily tesselated) and get pretty good fps!) , the method is used to avoid flickering).
Quick Note : when you are rendering multiple objects with different program3D make sure to null out the streams for example if program1 uses a texture and program2 does not, in this case you should null out the texture stream before you draw triangles using program2 like so : context3d.settextureat(0,null)....
i have been burned by this many times. if you dont do it you will end up getting the message : "texture stream is set but not used by the fragment shader".