How should I optimize drawing a large, dynamic number of collections of vertices?
...or am I insane to even try?
As a novice to using bare vertices for 3d graphics, I haven开发者_开发技巧't ever worked with vertex buffers and the like before. I am guessing that I should use a dynamic buffer because my game deals with manipulating, adding and deleting primitives. But how would I go about doing that?
So far I have stored my indices in a Triangle.cs class. Triangles are stored in Quads (which contain the vertices that correspond to their indices), quads are stored in blocks. In my draw method, I iterate through each block, each quad in each block, and finally each triangle, apply the appropriate texture to my effect, then call DrawUserIndexedPrimitives to draw the vertices stored in the triangle.
I'd like to use a vertex buffer because this method cannot support the scale I am going for. I am assuming it to be dynamic. Since my vertices and indices are stored in a collection of separate classes, though, can I still effectively use a buffer? Is using separate buffers for each quad silly (I'm guessing it is)? Is it feasible and effective for me to dump vertices into the buffer the first time a quad is drawn and then store where those vertices were so that I can apply that offset to that triangle's indices for successive draws? Is there a feasible way to handle removing vertices from the buffer in this scenario (perhaps event-based shifting of index offsets in triangles)?
I apologize that these questions may be either far too novicely or too confusing/vague. I'd be happy to provide clarification. But as I've said, I'm new to this and I may not even know what I'm talking about...
I can't exactly tell what you're trying to do, but using a seperate buffer for every quad is very silly.
The golden rule in graphics programming is batch, batch, batch. This means to pack as much stuff into a single DrawUserIndexedPrimitives call as possible, your graphics card will love you for it.
In your case, put all of your verticies and indicies into one vertex buffer and index buffer (you might need to use more, I have no idea how many verticies we're talking about). Whenever the user changes one of the primatives, regenerate the entire buffer. If you really have a lot of primatives, split them up into multiple buffers and on only regenerate the ones you need when the user changes something.
The most important thing is to minimize the amount of 'DrawUserIndexedPrimitives' calls, those things have a lot of overhead, you could easily make your game on the order of 20x faster. Graphics cards are pipelines, they like being given a big chunk of data for them to eat away at. What you're doing by giving it one triangle at a time is like forcing a large-scale car factory to only make one car at a time. Where they can't start on building the next car before the last one is finished.
Anyway good luck, and feel free to ask any questions.
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