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POOpenGL ES: glBufferSubData fills meshes into VBO/IBO, then glDrawElements renders only the first mesh instead of all of them
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  1. POOpenGL ES: glBufferSubData fills meshes into VBO/IBO, then glDrawElements renders only the first mesh instead of all of them
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    copied!<p>My problem seems to be really simple but I just can't get the reason behind it:</p> <ul> <li>I have a vertex and an index buffer that get filled in with glBufferSubData. There are a couple of meshes that get filled in one-by-one into this big VBO and its corresponding IBO</li> <li>Then I try to render those small meshes with glDrawElements one-by-one</li> </ul> <p>Problem is, only first mesh gets rendered - and multiple times - in places where each of those different meshes should be!!!</p> <p>Following info may be useful:</p> <p>I create VBO this way</p> <pre><code>gl.glGenBuffers(1, buffers_, 0); gl.glBindBuffer(GL11.GL_ARRAY_BUFFER, buffers_[0]); gl.glBufferData(GL11.GL_ARRAY_BUFFER, sizeInBytes, null, GL11.GL_DYNAMIC_DRAW); </code></pre> <p>Then each mesh is filled into the VBO like this</p> <pre><code>gl.glBindBuffer(GL11.GL_ARRAY_BUFFER, name); gl.glBufferSubData(GL11.GL_ARRAY_BUFFER, startOffsetInBytes, numBytesToCopy, nioBuffer); </code></pre> <p>And meshes are rendered in this fasion</p> <ul> <li>bind VBO/IBO and set appropriate client states</li> <li>then set vertex, normal, and texcoord "pointers" - they point at the beginning of VBO plus their offsets in vertex "structure"</li> <li>and call <code>gl.glDrawElements(GL10.GL_TRIANGLES, indicesNum, GL10.GL_UNSIGNED_SHORT, startIndexOffsetInBytes);</code></li> <li>then finally, unbind VBO/IBO and disable client states</li> </ul> <p>I debugged the code and I'm sure that <code>sizeInBytes</code>, <code>startOffsetInBytes</code>, <code>numBytesToCopy</code> and <code>startIndexOffsetInBytes</code> are correct values (in bytes:))) and <code>indicesNum</code> is the number of indices/vertices in the mesh (to render).</p> <p>One suspicious place is setting vertex/normal/texcoord pointers - they get set only once - and set to the beginning of the VBO. Maybe I need to set them each time before calling glDrawElements?</p>
 

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