DirectX 11 Transparency Issue

Question

I have a png file with a transparent background.

When i draw the image the transparency works.

as long as there is no other transparent image in front of it as seen below.

What changes do i need to make to my transparency code to solve this issue?

Depth stencil code:

// Initialize the description of the depth buffer.
ZeroMemory(&depthBufferDesc, sizeof(depthBufferDesc));

// Set up the description of the depth buffer.
depthBufferDesc.Width = screenWidth;
depthBufferDesc.Height = screenHeight;
depthBufferDesc.MipLevels = 1;
depthBufferDesc.ArraySize = 1;
depthBufferDesc.Format = DXGI_FORMAT_D24_UNORM_S8_UINT;
depthBufferDesc.SampleDesc.Count = 1;
depthBufferDesc.SampleDesc.Quality = 0;
depthBufferDesc.Usage = D3D11_USAGE_DEFAULT;
depthBufferDesc.BindFlags = D3D11_BIND_DEPTH_STENCIL;
depthBufferDesc.CPUAccessFlags = 0;
depthBufferDesc.MiscFlags = 0;

// Create the texture for the depth buffer using the filled out description.
result = m_device->CreateTexture2D(&depthBufferDesc, NULL, &m_depthStencilBuffer);
Error::ErrorCheck(result, TEXT("m_device->CreateTexture2D()"));

// Initialize the description of the stencil state.
ZeroMemory(&depthStencilDesc, sizeof(depthStencilDesc));

// Set up the description of the stencil state.
depthStencilDesc.DepthEnable = true;
depthStencilDesc.DepthWriteMask = D3D11_DEPTH_WRITE_MASK_ALL;
depthStencilDesc.DepthFunc = D3D11_COMPARISON_LESS;

depthStencilDesc.StencilEnable = true;
depthStencilDesc.StencilReadMask = 0xFF;
depthStencilDesc.StencilWriteMask = 0xFF;

// Stencil operations if pixel is front-facing.
depthStencilDesc.FrontFace.StencilFailOp = D3D11_STENCIL_OP_KEEP;
depthStencilDesc.FrontFace.StencilDepthFailOp = D3D11_STENCIL_OP_INCR;
depthStencilDesc.FrontFace.StencilPassOp = D3D11_STENCIL_OP_KEEP;
depthStencilDesc.FrontFace.StencilFunc = D3D11_COMPARISON_ALWAYS;

// Stencil operations if pixel is back-facing.
depthStencilDesc.BackFace.StencilFailOp = D3D11_STENCIL_OP_KEEP;
depthStencilDesc.BackFace.StencilDepthFailOp = D3D11_STENCIL_OP_DECR;
depthStencilDesc.BackFace.StencilPassOp = D3D11_STENCIL_OP_KEEP;
depthStencilDesc.BackFace.StencilFunc = D3D11_COMPARISON_ALWAYS;

// Create the depth stencil state.
result = m_device->CreateDepthStencilState(&depthStencilDesc, &m_depthStencilState);
Error::ErrorCheck(result, TEXT("m_device->CreateDepthStencilState()"));

// Set the depth stencil state.
m_deviceContext->OMSetDepthStencilState(m_depthStencilState, 0);

// Initailze the depth stencil view.
ZeroMemory(&depthStencilViewDesc, sizeof(depthStencilViewDesc));

// Set up the depth stencil view description.
depthStencilViewDesc.Format = DXGI_FORMAT_D24_UNORM_S8_UINT;
depthStencilViewDesc.ViewDimension = D3D11_DSV_DIMENSION_TEXTURE2D;
depthStencilViewDesc.Texture2D.MipSlice = 0;

// Create the depth stencil view.
result = m_device->CreateDepthStencilView(m_depthStencilBuffer, &depthStencilViewDesc, &m_depthStencilView);
Error::ErrorCheck(result, TEXT("m_device->CreateDepthStencilView()"));

// Bind the render target view and depth stencil buffer to the output render pipeline.
m_deviceContext->OMSetRenderTargets(1, &m_renderTargetView, m_depthStencilView);

Transparency code:

//Setup Blend State for transperency
D3D11_BLEND_DESC BlendStateDescription;
ZeroMemory(&BlendStateDescription, sizeof(D3D11_BLEND_DESC));

ID3D11BlendState* blend;

BlendStateDescription.RenderTarget[0].BlendEnable = TRUE;
BlendStateDescription.RenderTarget[0].RenderTargetWriteMask = D3D11_COLOR_WRITE_ENABLE_ALL;
BlendStateDescription.RenderTarget[0].SrcBlend = D3D11_BLEND_SRC_ALPHA;

BlendStateDescription.RenderTarget[0].DestBlend = D3D11_BLEND_INV_SRC_ALPHA;
BlendStateDescription.RenderTarget[0].SrcBlendAlpha = D3D11_BLEND_INV_DEST_ALPHA;
BlendStateDescription.RenderTarget[0].DestBlendAlpha = D3D11_BLEND_ONE;
BlendStateDescription.RenderTarget[0].BlendOp = D3D11_BLEND_OP_ADD;
BlendStateDescription.RenderTarget[0].BlendOpAlpha = D3D11_BLEND_OP_ADD;

m_device->CreateBlendState(&BlendStateDescription, &blend);
float blendFactor[] = { 0, 0, 0, 0 };
UINT sampleMask = 0xffffffff;

m_deviceContext->OMSetBlendState(blend, blendFactor, sampleMask);

Answer 1

Found the problem. Was in the depth buffer. Just a simple change depthStencilDesc.DepthFunc from D3D11_COMPARISON_LESS to D3D11_COMPARISON_LESS_EQUAL.

Found the answer here, follow link for more detailed description: Detailed answer