So I have been slowly reading and working through Frank Luna's D3D11 book which uses the .FX file format which uses effects, techniques and passes which I understand now. However I have read online that the FX framework is no longer supported so I shouldn't use it. How do .HLSL files work? Do techniques, passes and effects still work the same way? Can I still use functions like:


2 Answers 2


You can use the Effects for Direct3D 11 library (aka FX11), but should keep in mind that the HLSL compiler support for is deprecated, support for it exists "as is" (i.e. there are some known bugs in the fx_5_0 profile that will not get fixed), and may be removed in a future update. You should use the GitHub version of the runtime library as it has a number of fixes that are not present in the legacy DirectX SDK version.

As to your original question, here's some info from the soon to be defunct CodePlex: What's the difference between an .fx and .hlsl file anyhow?

Historically the extension '.fx' refers to a HLSL shader intended to be built using the legacy effects fx_4_0, fx_5_0, etc. profiles; while '.hlsl' refers to individual HLSL shaders. The reality is that there's no consistency here. You will see lots of '.fx' files without any technique/pass statements.

Unlike C/C++ source files, HLSL files can contain a lot of stuff that gets ignored in a given invocation of the compiler. If you have a big .fx file with a dozen shaders in it and a bunch of technique/passes, you can compile the same file many times with different entry-points and profiles to generate lots of shaders.

It's really all a matter of how you want to build your shader content. For example, DirectX Tool Kit uses a command-line script to build all the possible combinations of shaders: currrently it builds 86 shader blobs from 7 .fx files (and actually it can build them twice: once with the Windows compiler and once with the Xbox One XDK compiler, but only one set of these shader blobs is included in a given build of the DirectXTK.lib anyhow).

If you use the Visual Studio 2012/2013 content pipeline to build your shaders, you do have to deal with a limitation of MSBuild which assumes each source file is built once for each result. So in that case, you'd want an individual '.hlsl' file for each shader combination (which for the DirectX Tool Kit example would mean 86 '.hlsl' files). One way to handle this would be to keep the shader source itself in a single file, and then have a bunch of .hlsl files that #include the 'source' file. Something like:

#include "BasicEffect.fx"
#include "BasicEffect.fx"

You then compile each of these .hlsl files once with the proper shader profile and entry-point. This approach works fine for smaller projects, but doesn't scale well to large complex shaders without using legacy fx profiles. In that case, other build solutions like DirectX Tool Kit's build solution is probably better.

If you are using legacy fx profiles, you of course only have to compile each .fx once and it will generate all the shaders it specifies in technique/passes in one go.

Frank Luna's Direct3D 11 book is a victim of its timing. It was published just prior to the legacy DirectX SDK being deprecated. The basics of the book are great, but FX11, D3DX11, and XNAMath all have replacements that avoid using the legacy DirectX SDK. See Living without D3DX, Introducing DirectXMath, and Book Recommendations.

UPDATE: While it's still strongly recommended that you not use D3DX9, D3DX10, or D3DX11 in new projects, for tutorials or books like Luna's that assume you have the legacy DirectX SDK installed, there's now an easier-to-use solution for modern toolsets: use the NuGet package Microsoft.DXSDK.D3DX. See this blog post for details.

Effects was always an optional system which made it easier to bind a group of related shaders and state based on a file format. You don't need Effects, and you can always compile the fx file multiple times for each permutation of the individual shaders and handle setting up all the related state yourself.

If you are new to Direct3D 11 development, you should take a look at DirectX Tool Kit and it's tutorials as it provides a number of 'stock' shaders which can get you a long way.



The Effects framework, and .fx files, were something like a container wrapper for shaders and state associated with those shaders. "Techniques" and "passes" are concepts introduced by the Effects framework, and don't exist otherwise unless you build your own abstraction.

Pixel/vertex shaders alone will just contain the code for the shader itself, and declarations of input uniforms and so on. Binding and supplying values for those uniforms and setting up any rendering state the shader wants to assume are all your responsibility when you leave the Effects framework behind.

  • \$\begingroup\$ I think you might've misunderstood my question, what I meant was that how can I write a shader for SSAO for example and get it to work with the other shaders. When I make a draw call should I also call a function to change the Vertex and Pixel Shaders along with the Cbuffer data? With the FX framework I could use techniques and passes to do this but how about with the new method? \$\endgroup\$ Sep 13, 2016 at 14:28
  • \$\begingroup\$ Well your original question doesn't mention SSAO, changing shaders, constant buffers, or any of that. If that's what you want information about you have to include it in your question. Nobody can read your mind. \$\endgroup\$
    – user1430
    Sep 13, 2016 at 15:14
  • 1
    \$\begingroup\$ That said, you can only have one shader of each stage (vertex, pixel, et cetera) active at once. If you need multiple passes over your rendered frame, you will need to write and bind multiple shaders (assuming each pass is doing something different) in a row, along with any inputs and constant buffers you need for those shaders. All manually. \$\endgroup\$
    – user1430
    Sep 13, 2016 at 15:16

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