Hi,

I'm trying to bind multiple rendertargets. RT0 is working without any problems but if I switch to RT1 or higher, I got a crash in "pd3dImmediateContext->OMSetRenderTargets(numberRenderTargets, &_pRenderTargetView, _pDepthStencilView);".
I think it's my init-code (because 0 is working and if I swap RT0 and RT1 it's also working)

I read this post http://www.gamedev.net/topic/518035-dx10-deferred-rendering-and-render-to-multiple-render-targets/
and would like to know what to do when having a Texture2DArray.

Something like that:

[source lang="cpp"]
D3D11_TEXTURE2D_DESC td_target;
td_target.ArraySize = number_rendertargets;
//bla bla

pd3dDevice->CreateTexture2D(&td_target, NULL, &_pRenderTargetBuffer);

D3D11_RENDER_TARGET_VIEW_DESC rd_rendertargetview;
//Zero...
rd_rendertargetview.ViewDimension = D3D11_RTV_DIMENSION_TEXTURE2DARRAY;
rd_rendertargetview.Texture2DArray.ArraySize = number_rendertargets;
//etc.

pd3dDevice->CreateRenderTargetView(_pRenderTargetBuffer, &rd_rendertargetview, &_pRenderTargetView);
//with: ID3D11RenderTargetView* _pRenderTargetView;
[/source]

Does _pRenderTargetView have to be an "ID3D11RenderTargetView* _pRenderTargetView[number_rendertargets];"? (with more calls to CreateRenderTargetView)

Thanks!

Hm, ok let's see...

I want to bind an array of Textures to my graphic pipeline (multiple rendertargets).
Therefore I created a Textrue2D with "ArraySize" 8.
To bind it to the pipeline, one or more rendertargetview(s) are needed.

My question:
Is one rendertargetview enough (as it is with Texture2D where I just create one logical structure with only an additional parameter)
or do I have to build up an array of rendertargetviews manually?

[source lang="cpp"]
ID3D11Texture2D* RenderTargetBuffer; //no RenderTargetBuffer[8]...
ID3D11RenderTargetView* RenderTargetView; //...here too: just ONE structure

//create Texture2D with parameter "ArraySize" 8

D3D11_RENDER_TARGET_VIEW_DESC rendertargetview_desc;
rendertargetview_desc.Texture2DArray.ArraySize = 8;
//fill rest of desc

pd3dDevice->CreateRenderTargetView(RenderTargetBuffer, rendertargetview_desc, RenderTargetView);
[/source]

----- OR -----

[source lang="cpp"]
ID3D11Texture2D* RenderTargetBuffer; //no RenderTargetBuffer[8]...
ID3D11RenderTargetView* RenderTargetView[8]; //...but here: create 8 manually!

//create Texture2D with parameter "ArraySize" 8

//rendertargetview_desc: no parameter "ArraySize" set
//fill rest of desc

for(int i = 0; i < 8; ++i){
pd3dDevice->CreateRenderTargetView(RenderTargetBuffer->get(i), rendertargetview_desc, RenderTargetView);
}
[/source]


I didn't find any "RenderTargetBuffer->get(i)" function at the documentation (so I think possibility 1 seems right).
But I found that link from above, saying you have to build up the array manually (=> possibility 2 seems right, but no get-function)

[source lang="cpp"]
//source code from link (copy&paste)
ID3D10RenderTargetView* pRTViews[8] = {NULL, NULL, NULL, ... } //array manually!

CreateRenderTargetView(rtTex1, &pRTViews[0])
CreateRenderTargetView(rtTex2, &pRTViews[1])
[/source]

I can't find any documentation to this and only get a black screen with possibility 1 when using rendertarget1-7 (but rendertarget0 is working!)... :-/

So, how do I implement multiple rendertargets with the Texture2D and ArraySize shown above?
(or is it not possible and I have to do something completely different?)

Thank you

Thanks for the detailed answer. Now I understand what smasherprog meant by "include more code".

I'm trying to implement some kind of anti aliasing. To improve this I want to jitter coordinates of the mesh in my geometry-shader.
So I'm rendering the same mesh with different (jittered) positions. Finally it's evaluated in a postprocess.

Sounds like the MRT is the right way to do this (?), because I have the same stages (except the GS) and same rasterizer.
I already implemented the shaders (GS sets SV_RenderTargetArrayIndex, Pixelshader reads it and writes SV_Target).

When I got it right, I have to create more rendertargets ("RenderTargetView[8]" = possibility 2).
Is there a function for "RenderTargetBuffer->get(i)"? (didn't find any in the msdn documentation)


At the moment my code looks like this:
[source lang="cpp"]
ID3D11Texture2D* _pRenderTargetBuffer;
ID3D11RenderTargetView* _pRenderTargetView; //should be RenderTargetView[8]?

//...

D3D11_TEXTURE2D_DESC td_target;
ZeroMemory(&td_target, sizeof(D3D11_TEXTURE2D_DESC));
td_target.Width = _width;
td_target.Height = _height;
td_target.MipLevels = 1; //no mipmap
td_target.ArraySize = _number_rendertargets;
td_target.Format = DXGI_FORMAT_R32G32B32A32_FLOAT;
td_target.Usage = D3D11_USAGE_DEFAULT;
td_target.BindFlags = D3D11_BIND_RENDER_TARGET | D3D11_BIND_SHADER_RESOURCE;
td_target.CPUAccessFlags = 0; //no cpu access
td_target.MiscFlags = 0;
td_target.SampleDesc.Count = 1;
td_target.SampleDesc.Quality = 0;

pd3dDevice->CreateTexture2D(&td_target, NULL, &_pRenderTargetBuffer);

D3D11_RENDER_TARGET_VIEW_DESC rd_rendertargetview;
ZeroMemory(&rd_rendertargetview, sizeof(D3D11_RENDER_TARGET_VIEW_DESC));
rd_rendertargetview.ViewDimension = D3D11_RTV_DIMENSION_TEXTURE2DARRAY;
rd_rendertargetview.Format = td_target.Format;
rd_rendertargetview.Texture2DArray.ArraySize = _number_rendertargets;
rd_rendertargetview.Texture2DArray.FirstArraySlice = 0;
rd_rendertargetview.Texture2DArray.MipSlice = 0;

//how do I get the right buffer out of the _pRenderTargetBuffer array if I have RenderTargetView[8] here?
pd3dDevice->CreateRenderTargetView(_pRenderTargetBuffer, &rd_rendertargetview, &_pRenderTargetView);
[/source]

Do you also need the render code or the shader code?

Thanks again :-)

Yes, I want to output multiple copies of the same geometry in the geometry shader.
RTA sounds like what I already did. (one Render Target View, representing an array of buffers)

I'll have a look at that demo, thank you very much for the hints and explanation.

I got it work, but I've got some strange effects. Perhaps someone can explain that to me.
Rendertarget Array is bound to pipeline and is working.

I tried different Pixelshaders (SV_RenderTargetArrayIndex "rta_index" is set by Geometryshader) and the size of the Rendertarget Array can be set during runtime.

1) Is working with every size of RT Array:

[source lang="cpp"]
struct PS_Out{
float4 Color : SV_TARGET;
};

PS_Out PShader(GS_Out input){
PS_Out output;
output.Color = input.vColor;
return output;
}
[/source]

2) Is also working with every size of RTA, ALSO WITH rta_index BIGGER THAN 3!!!

[source lang="cpp"]
struct PS_Out{
float4 Color0 : SV_TARGET0;
float4 Color1 : SV_TARGET1;
float4 Color2 : SV_TARGET2;
float4 Color3 : SV_TARGET3;
float4 Color4 : SV_TARGET4;
float4 Color5 : SV_TARGET5;
float4 Color6 : SV_TARGET6;
float4 Color7 : SV_TARGET7;
};

PS_Out PShader(GS_Out input){
PS_Out output;

if(input.rta_index == 0){
output.Color0 = input.vColor;
}
else if(input.rta_index == 1){
output.Color1 = input.vColor;
}
else if(input.rta_index == 2){
output.Color2 = input.vColor;
}
else if(input.rta_index == 3){
output.Color3 = input.vColor;
}
//no else!

return output;
}
[/source]

3) The one I think should work, but isn't! Only RTA 0 is filled correctly, rest: mesh is black, background is blue (clear color is blue!):

[source lang="cpp"]
struct PS_Out{
float4 Color0 : SV_TARGET0;
float4 Color1 : SV_TARGET1;
float4 Color2 : SV_TARGET2;
float4 Color3 : SV_TARGET3;
float4 Color4 : SV_TARGET4;
float4 Color5 : SV_TARGET5;
float4 Color6 : SV_TARGET6;
float4 Color7 : SV_TARGET7;
};

PS_Out PShader(GS_Out input){
PS_Out output;

if(input.rta_index == 0){
output.Color0 = input.vColor;
}
else if(input.rta_index == 1){
output.Color1 = input.vColor;
}
else if(input.rta_index == 2){
output.Color2 = input.vColor;
}
else if(input.rta_index == 3){
output.Color3 = input.vColor;
}
else if(input.rta_index == 4){
output.Color4 = input.vColor;
}
else if(input.rta_index == 5){
output.Color5 = input.vColor;
}
else if(input.rta_index == 6){
output.Color6 = input.vColor;
}
else if(input.rta_index == 7){
output.Color7 = input.vColor;
}
//no else! (but there can only be 8 rendertargets be bound => 7 should be maximum)

return output;
}
[/source]


I do not understand why 2) should work and 3) isn't. And I also don't understand how 1) knows which SV_Target to fill.

Can someone explain that to me? Thanks very much!

Is there no explanation for this behaviour?