I'm trying to write my first DX12 app. I have no previous experience in DX11. I would like to display some rigid and some soft objects. Without textures for now. So I need to place into GPU some vertex/index buffers which I will never change later and some which I will change. And the scene per se isn't static, so some new objects can appear and some can vanish.
How should I allocate/populate/update memory on GPU for it? I would like to see high level overview easy to read and understand, not real code. Hope the question isn't too broad.
You said you are new to DirectX, i will strongly recommend you to stay away from DX12 and stick with DX11. DX12 is only useful for people that are already Expert ( with a big E ) and project that has to push very far or have edge cases for a feature in DX12 not possible in DX11.
But anyway, on DX12, as an example to initialize a buffer, you have to create instances of ID3D12Resource. You will need two, one in the an upload heap and one in the default heap. You fill the first one on the CPU using Map. Then you need to use a command list to copy to the second one. Of course, you have to manage the resource state of your resource with barriers ( copy destination, shader resource, ... ). You need then to execute the command list on the command queue. You also need to add a fence to listen the gpu for completion before you can destroy the resource in the upload heap.
On DX11, you call ID3D11Device::CreateBuffer, by providing the description struct with a SRV binding flag and the pointer to the cpu data you want to put in it… Done
It is slightly more complex for texture as you deal with memory layout. So, as i state above, you should focus on DX11, it is not degrading at all, both have their roles.