Comments on: Direct3D 10 to Direct3D 11: How to Transpose Your Matrices

By: Jeff Stryker

Jeff Stryker — Fri, 27 Sep 2013 15:54:38 +0000

It’s actually not a myth, and it’s nothing to do with left-handed or right-handed – DX9 can handle either handedness fine. And whether the internal storage is transposed is irrelevant. What matters is that when you take a 16-float chunk of data and send it as a D3DXMATRIX to DX9, and take the same chunk and send it to GL using glUniformMatrix4fv, or in a constant buffer, you have to transpose one of them in order to get the same result from a premultiply operation. As of DX11, you can use the SAME CODE to set up a constant buffer for GL or DX11, and send that buffer to the shader. Then a premultiply will work the same for either.

By: Grandmaster B

Grandmaster B — Sat, 26 Jun 2010 15:36:41 +0000

Its a myth that OpenGL matrices are transposed in relation to Direct3D 10 and before. Both APIs had the same matrix storage order they just used a different math convention in their documentation – therefore the myth.

You can easily check that by using glRotate and glTranslate. There was (or is?) also an official statement on opengl.org.

The one thing that is different is the corrdinate system, while Direct3D uses a left-handed coordinate system, OpenGL uses a right-handed coordinate system, this needs a matrix conversion of the view matrix – for example.

By: hint

hint — Fri, 25 Jun 2010 08:03:04 +0000

No need to transpose your matrices before uploading them to the GPU. You can simply use the row_major keyword in your HLSL code.

By: DrBalthar

DrBalthar — Wed, 23 Jun 2010 13:01:15 +0000

You are aware that there is setMatrixTranspose in D3D Effect?

And you are also aware that D3DXMATH is replaced with XNAMath?

By: Mars_999

Mars_999 — Tue, 22 Jun 2010 19:41:13 +0000

Ha, maybe DX11 should be a wrapper around OpenGL! 🙂

By: somari

somari — Tue, 22 Jun 2010 15:50:18 +0000

Wait, wait.
In GLSL, there’s this:

mat4 m1;
mat4 m2; // = transposed m1
vec4 v;

m1*v == v*m2;

By: Lokavidu

Lokavidu — Tue, 22 Jun 2010 15:14:39 +0000

nice tip, thx 🙂