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Posted 26 April 2012 - 01:12 AM
I read these articles on texture streaming for some ideas:
http://home.comcast.net/~tom_forsyth/blog.wiki.html (Visibility and priority tests for streaming assets)
I plan on starting slow and just making resources load in as needed, and when doing so, kick out any resources that haven't been used in 90 seconds.
My plan for later is to keep things in memory for a while and only kick them out if the memory usage is high enough. Only problem is knowing what that memory usage level is. For textures, would it basically be something around the Video memory? How bout meshes, or audio, and so on... That's what I'm really confused about right now.
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Posted 26 April 2012 - 12:59 PM
If so, then if you don't ever need more than 1 or 2 MIP levels, aren't you wasting texture space? (there will be 4 or 5 MIP levels available and waiting in that texture with no use).
The only other way I can see it working is it you have a pool of different-sized textures with 1 MIP level, a pool with 2 MIP levels, a pool with 3, and so on and as you get closer to textures, you switch all the already-loaded MIP levels over to the next available '+1 MIP level' texture and load the next MIP level. But then this might introduce some latency with swapping texture data around...
Any thoughts on the OP's question and/or this?
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Posted 26 April 2012 - 01:43 PM
It might be a bit of a waste of memory, but you allocate all mips in the texture you are streaming, but actually only load up to the one you need at that moment. The benefit comes from gradually loading in only what you need instead of all at once.
There's even more added complexity when you start adding prediction and priorities to resources. Like, how do you assign the different priorities, and at what memory usage do you start kicking out the lower priority resources. You could say, oh just use video memory, and track how much memory the textures are using, but then you also have your meshes, shaders, and a bunch of other things taking up video memory. Now you have to balance those objects too, do I allocate some percentage of memory for textures, some percentage for meshes? I don't even know how to begin figuring out memory usage for other things like shaders or how any of that stuff works.
Then there's sound and other resources. You have a computer with some varying amount of memory and some varying processes running taking up random amounts of memory. On consoles it's all set in stone more or less, but on PC, how would I determine if I'm using too much memory for sound effects and so forth. And video memory isn't fixed on PC's either since different cards have different memory.
For a much simpler game a simpler resource manager would probably do just fine...