Jump to content
  • Advertisement

DX11 Rendering CS output to backbuffer [SOLVED]

Recommended Posts

SOLVED: I had written 

Dispatch(32, 24, 0)

instead of

Dispatch(32, 24, 1)

 

 

I'm attempting to implement some basic post-processing in my "engine" and the HLSL part of the Compute Shader and such I think I've understood, however I'm at a loss at how to actually get/use it's output for rendering to the screen.

Assume I'm doing something to a UAV in my CS:

RWTexture2D<float4> InputOutputMap : register(u0);

I want that texture to essentially "be" the backbuffer.

 

I'm pretty certain I'm doing something wrong when I create the views (what I think I'm doing is having the backbuffer be bound as render target aswell as UAV and then using it in my CS):
 

	DXGI_SWAP_CHAIN_DESC scd;
	ZeroMemory(&scd, sizeof(DXGI_SWAP_CHAIN_DESC));

	scd.BufferCount = 1;                                   
	scd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;     
	scd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT | DXGI_USAGE_SHADER_INPUT | DXGI_USAGE_UNORDERED_ACCESS;
	scd.OutputWindow = wndHandle;  
	scd.SampleDesc.Count = 1;  
	scd.Windowed = TRUE; 
						
	HRESULT hr = D3D11CreateDeviceAndSwapChain(NULL,
		D3D_DRIVER_TYPE_HARDWARE,
		NULL,
		NULL,
		NULL,
		NULL,
		D3D11_SDK_VERSION,
		&scd,
		&gSwapChain,
		&gDevice,
		NULL,
		&gDeviceContext);

	// get the address of the back buffer
	ID3D11Texture2D* pBackBuffer = nullptr;
	gSwapChain->GetBuffer(0, __uuidof(ID3D11Texture2D), (LPVOID*)&pBackBuffer);

	// use the back buffer address to create the render target
	gDevice->CreateRenderTargetView(pBackBuffer, NULL, &gBackbufferRTV);

	// set the render target as the back buffer
	CreateDepthStencilBuffer();

	gDeviceContext->OMSetRenderTargets(1, &gBackbufferRTV, depthStencilView);

	//UAV for compute shader
	D3D11_UNORDERED_ACCESS_VIEW_DESC uavd;
	ZeroMemory(&uavd, sizeof(uavd));

	uavd.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
	uavd.ViewDimension = D3D11_UAV_DIMENSION_TEXTURE2D;
	uavd.Texture2D.MipSlice = 1;
		
	gDevice->CreateUnorderedAccessView(pBackBuffer, &uavd, &gUAV);

	pBackBuffer->Release();

 

After I render the scene, I dispatch like this:


	gDeviceContext->OMSetRenderTargets(0, NULL, NULL);
	m_vShaders["cs1"]->Bind();
	gDeviceContext->CSSetUnorderedAccessViews(0, 1, &gUAV, 0);
	gDeviceContext->Dispatch(32, 24, 0); //hard coded

	ID3D11UnorderedAccessView* nullview = { nullptr };
	gDeviceContext->CSSetUnorderedAccessViews(0, 1, &nullview, 0);
	gDeviceContext->OMSetRenderTargets(1, &gBackbufferRTV, depthStencilView);

	gSwapChain->Present(0, 0);

Worth noting is the scene is rendered as usual, but I dont get any results from the CS (simple gaussian blur)

I'm sure it's something fairly basic I'm doing wrong, perhaps my understanding of render targets / views / what have you is just completely wrong and my approach just makes no sense.

If someone with more experience could point me in the right direction I would really appreciate it!

On a side note, I'd really like to learn more about this kind of stuff. I can really see the potential of the CS aswell as rendering to textures and using them for whatever in the engine so I would love it if you know some good resources I can read about this!

Thank you <3

 

P.S I excluded the .hlsl since I cant imagine that being the issue, but if you think you need it to help me just ask


P:P:S. As you can see this is my first post however I do have another account, but I can't log in with it because gamedev.net just keeps asking me to accept terms and then logs me out when I do over and over

Edited by GreenGodDiary
solved

Share this post


Link to post
Share on other sites
Advertisement

Update:

Been trying to figure it out on my own, using Graphics Debugging in VStudio shows that the UAV and resource are correct in the CS, but the history for the resource shows that the Dispatch-call writes to it but doesnt change it (i think?)

91096550af06934ec00d0b4548a1a67b.png

 

So, maybe it is my shader code after all?

It is taken from Practical Rendering and Computation with Direct3D 11 with minimal change, since their version used a separate input resource (SRV), while I use the UAV for both input and output.
Anyway here's the shader:

// Declare the input and output resources
//Texture2D<float4> InputMap : register(t0);
RWTexture2D<float4> InputOutputMap : register(u0);

// Group size
#define size_x 32
#define size_y 32
  
// Declare the filter kernel coefficients
static const float filter[7][7] = {
	0.000904706, 0.003157733, 0.00668492, 0.008583607, 0.00668492,
	0.003157733, 0.000904706,
	0.003157733, 0.01102157, 0.023332663, 0.029959733, 0.023332663,
	0.01102157, 0.003157733,
	0.00668492, 0.023332663, 0.049395249, 0.063424755, 0.049395249,
	0.023332663, 0.00668492,
	0.008583607, 0.029959733, 0.063424755, 0.081438997, 0.063424755,
	0.029959733, 0.008583607,
	0.00668492, 0.023332663, 0.049395249, 0.063424755, 0.049395249,
	0.023332663, 0.00668492,
	0.003157733, 0.01102157, 0.023332663, 0.029959733, 0.023332663,
	0.01102157, 0.003157733,
	0.000904706, 0.003157733, 0.00668492, 0.008583607, 0.00668492,
	0.003157733, 0.000904706
};
// Declare one thread for each texel of the current block size.
[numthreads(size_x, size_y, 1)]
void CS_main(uint3 DispatchThreadID : SV_DispatchThreadID)
{
		//Offset the texture location to the first sample location
		int3 texturelocation = DispatchThreadID - int3(3, 3, 0);
  
		//Initialize the output value to zero, then loop through the
		// filter samples, apply them to the image samples, and sum
		// the results.
		float4 Color = float4(0.0, 0.0, 0.0, 0.0);
		for (int x = 0; x < 7; x++)
		{
			for (int y = 0; y < 7; y++)
			{
				Color += InputOutputMap.Load(texturelocation + int3(x, y, 0)) * filter[x][y];
			}
		}
		// Write the output to the output resource
		InputOutputMap[DispatchThreadID.xy] = Color;
}


It looks good to me and it compiles fine, and it might be, but something I'm obviously doing wrong.

Another thing the Graphics Debugger tells me is this:

da99e38065b911d70fdc7f6b9eefc25f.png

 

No effect: makes little sense to me, looking at my shader code.
Occluded: how? I do not touch the resource after the Dispatch, and since im explicitly overwriting every pixel I dont see how it could become occluded from any previous operations.

Any pointers appreciated!

Share this post


Link to post
Share on other sites

Small note: ZeroMemory was introduced for C# programmers wanting to write C++, you can just do = {}; (braced initializer) as well.

Edited by matt77hias

Share this post


Link to post
Share on other sites
4 hours ago, matt77hias said:

Small note: ZeroMemory was introduced for C# programmers wanting to write C++, you can just do = {}; (braced initializer) as well.

Good to know! Thanks :)

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Advertisement
  • Advertisement
  • Popular Tags

  • Popular Now

  • Advertisement
  • Similar Content

    • By chiffre
      Introduction:
      In general my questions pertain to the differences between floating- and fixed-point data. Additionally I would like to understand when it can be advantageous to prefer fixed-point representation over floating-point representation in the context of vertex data and how the hardware deals with the different data-types. I believe I should be able to reduce the amount of data (bytes) necessary per vertex by choosing the most opportune representations for my vertex attributes. Thanks ahead of time if you, the reader, are considering the effort of reading this and helping me.
      I found an old topic that shows this is possible in principal, but I am not sure I understand what the pitfalls are when using fixed-point representation and whether there are any hardware-based performance advantages/disadvantages.
      (TLDR at bottom)
      The Actual Post:
      To my understanding HLSL/D3D11 offers not just the traditional floating point model in half-,single-, and double-precision, but also the fixed-point model in form of signed/unsigned normalized integers in 8-,10-,16-,24-, and 32-bit variants. Both models offer a finite sequence of "grid-points". The obvious difference between the two models is that the fixed-point model offers a constant spacing between values in the normalized range of [0,1] or [-1,1], while the floating point model allows for smaller "deltas" as you get closer to 0, and larger "deltas" the further you are away from 0.
      To add some context, let me define a struct as an example:
      struct VertexData { float[3] position; //3x32-bits float[2] texCoord; //2x32-bits float[3] normals; //3x32-bits } //Total of 32 bytes Every vertex gets a position, a coordinate on my texture, and a normal to do some light calculations. In this case we have 8x32=256bits per vertex. Since the texture coordinates lie in the interval [0,1] and the normal vector components are in the interval [-1,1] it would seem useful to use normalized representation as suggested in the topic linked at the top of the post. The texture coordinates might as well be represented in a fixed-point model, because it seems most useful to be able to sample the texture in a uniform manner, as the pixels don't get any "denser" as we get closer to 0. In other words the "delta" does not need to become any smaller as the texture coordinates approach (0,0). A similar argument can be made for the normal-vector, as a normal vector should be normalized anyway, and we want as many points as possible on the sphere around (0,0,0) with a radius of 1, and we don't care about precision around the origin. Even if we have large textures such as 4k by 4k (or the maximum allowed by D3D11, 16k by 16k) we only need as many grid-points on one axis, as there are pixels on one axis. An unsigned normalized 14 bit integer would be ideal, but because it is both unsupported and impractical, we will stick to an unsigned normalized 16 bit integer. The same type should take care of the normal vector coordinates, and might even be a bit overkill.
      struct VertexData { float[3] position; //3x32-bits uint16_t[2] texCoord; //2x16bits uint16_t[3] normals; //3x16bits } //Total of 22 bytes Seems like a good start, and we might even be able to take it further, but before we pursue that path, here is my first question: can the GPU even work with the data in this format, or is all I have accomplished minimizing CPU-side RAM usage? Does the GPU have to convert the texture coordinates back to a floating-point model when I hand them over to the sampler in my pixel shader? I have looked up the data types for HLSL and I am not sure I even comprehend how to declare the vertex input type in HLSL. Would the following work?
      struct VertexInputType { float3 pos; //this one is obvious unorm half2 tex; //half corresponds to a 16-bit float, so I assume this is wrong, but this the only 16-bit type I found on the linked MSDN site snorm half3 normal; //same as above } I assume this is possible somehow, as I have found input element formats such as: DXGI_FORMAT_R16G16B16A16_SNORM and DXGI_FORMAT_R16G16B16A16_UNORM (also available with a different number of components, as well as different component lengths). I might have to avoid 3-component vectors because there is no 3-component 16-bit input element format, but that is the least of my worries. The next question would be: what happens with my normals if I try to do lighting calculations with them in such a normalized-fixed-point format? Is there no issue as long as I take care not to mix floating- and fixed-point data? Or would that work as well? In general this gives rise to the question: how does the GPU handle fixed-point arithmetic? Is it the same as integer-arithmetic, and/or is it faster/slower than floating-point arithmetic?
      Assuming that we still have a valid and useful VertexData format, how far could I take this while remaining on the sensible side of what could be called optimization? Theoretically I could use the an input element format such as DXGI_FORMAT_R10G10B10A2_UNORM to pack my normal coordinates into a 10-bit fixed-point format, and my verticies (in object space) might even be representable in a 16-bit unsigned normalized fixed-point format. That way I could end up with something like the following struct:
      struct VertexData { uint16_t[3] pos; //3x16bits uint16_t[2] texCoord; //2x16bits uint32_t packedNormals; //10+10+10+2bits } //Total of 14 bytes Could I use a vertex structure like this without too much performance-loss on the GPU-side? If the GPU has to execute some sort of unpacking algorithm in the background I might as well let it be. In the end I have a functioning deferred renderer, but I would like to reduce the memory footprint of the huge amount of vertecies involved in rendering my landscape. 
      TLDR: I have a lot of vertices that I need to render and I want to reduce the RAM-usage without introducing crazy compression/decompression algorithms to the CPU or GPU. I am hoping to find a solution by involving fixed-point data-types, but I am not exactly sure how how that would work.
    • By cozzie
      Hi all,
      I was wondering it it matters in which order you draw 2D and 3D items, looking at the BeginDraw/EndDraw calls on a D2D rendertarget.
      The order in which you do the actual draw calls is clear, 3D first then 2D, means the 2D (DrawText in this case) is in front of the 3D scene.
      The question is mainly about when to call the BeginDraw and EndDraw.
      Note that I'm drawing D2D stuff through a DXGI surface linked to the 3D RT.
      Option 1:
      A - Begin frame, clear D3D RT
      B - Draw 3D
      C - BeginDraw D2D RT
      D - Draw 2D
      E - EndDraw D2D RT
      F - Present
      Option 2:
      A - Begin frame, clear D3D RT + BeginDraw D2D RT
      B - Draw 3D
      C - Draw 2D
      D - EndDraw D2D RT
      E- Present
      Would there be a difference (performance/issue?) in using option 2? (versus 1)
      Any input is appreciated.
    • By Sebastian Werema
      Do you know any papers that cover custom data structures like lists or binary trees implemented in hlsl without CUDA that work perfectly fine no matter how many threads try to use them at any given time?
    • By cozzie
      Hi all,
      Last week I noticed that when I run my test application(s) in Renderdoc, it crashes when it enable my code that uses D2D/DirectWrite. In Visual Studio no issues occur (debug or release), but when I run the same executable in Renderdoc, it crashes somehow (assert of D2D rendertarget or without any information). Before I spend hours on debugging/ figuring it out, does someone have experience with this symptom and/or know if Renderdoc has known issues with D2D? (if so, that would be bad news for debugging my application in the future );
      I can also post some more information on what happens, code and which code commented out, eliminates the problems (when running in RenderDoc).
      Any input is appreciated.
    • By lonewolff
      Hi Guys,
      I understand how to create input layouts etc... But I am wondering is it at all possible to derive an input layout from a shader and create the input layout directly from this? (Rather than manually specifying the input layout format?)
      Thanks in advance :)
       
  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

Participate in the game development conversation and more when you create an account on GameDev.net!

Sign me up!