Pass changes to a mesh to GPU using VBO ->only pass changes about upbge HOT 8 CLOSED

It's interesting, But, how to detect which vertices are modified ? Set a modification flag per vertices ?
If this is the only case we need first to optimize data send to the VBO.

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how about when we move a vert or change the vertex color , add it to the list?

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So just a list of index of vertices ? maybe the index + a modifiaction flag like the current one in RAS_MeshObject.
e.g:

struct VertexModified
{
unsigned int index;
char flag;
}

So it will be :

RAS_MeshObject::SetVeterxModified(array, VertexModified(index, RAS_MeshObject::POSITION_MODIFIED)

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To reduce the glBufferSubData call i have an idea:
We store all vertex index in a list, we sort the index and iterate on all indices.
If an index = next_index - 1 we remove the index (if it's not the first one). By doing this we will get a list of continuous modified vertexes, e.g:
0:9, 16:18, 150:201

After this sort stage, we use glMapBufferRange to update these part of the buffer (iirc we can multi thread these call) and finally a glUnmapBuffer.

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Would this be compatible with GLSL shaders already compiled (gpu_material.c and gpu_shader_material.glsl) that use gl_Vertex?

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Why did you close this?

On Sun, Jul 24, 2016 at 8:37 AM, Diego Lopes [email protected]
wrote:

Closed #42 #42.

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I have a better approach. Whenever the user calls the method to change a vertex or the vertex data, switch a boolean isChanged to true, then before rendering check if it has been changed. Then switch the isChanged variable back to false and update the vertex data in the VBO.

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This is already done by the RAS_MeshObject::m_modifiedFlag and RAS_IStorageInfo::SetMeshModified.

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