standard "untweakables" mapping

Graphics Shaders & Materials
1

Hi friends,

pretty much every shader I open from nvidia’s website has declaration of standard ‘untweakables’.
For example:

/************* "UN-TWEAKABLES" TRACKED BY CPU APPLICATION **************/
float4x4 AimWorldITXf : WorldInverseTranspose <string UIWidget="None";>;
float4x4 AimWorldXf : World <string UIWidget="None";>;
float4x4 AimViewIXf : ViewInverse <string UIWidget="None";>;
float4x4 AimWorldViewProjXf : WorldViewProjection <string UIWidget="None";>;
float4x4 AimWorldViewITXf : WorldViewInverseTranspose <string UIWidget="None";>;
float4x4 AimWorldViewXf : WorldView <string UIWidget="None";>;
float4x4 AimViewXf : View <string UIWidget="None";>;
float4x4 AimViewITXf : ViewInverseTranspose <string UIWidget="None";>;

Now this looks somewhat intimidating, but it seems to me that you can calculate all these matrices by taking inverse or transpose or combinations of these 3 matrices:
View
World
Projection
So what are these matrices in Unity?

I am going to guess:
View → there isn’t one. You need to supply it from scipt.
World → _Object2World
Projection → UNITY_MATRIX_P

some transformations/combinations of these matrices readily available:
WorldViewProjection → UNITY_MATRIX_MVP
WorldView → UNITY_MATRIX_MV
WorldViewTranspose → UNITY_MATRIX_T_MV
WorldViewInverseTranspose → UNITY_MATRIX_IT_MV
WorldInverse → _World2Object

please correct me if I am wrong.

2

seems correct,also,those charts are useful when trying to construct matrices in script and passing them to shader,you need to flip some elements

390248--13423--$gl2d3dm2_898.png
390248--13424--$gl2d3dm1_544.png

3

Where are those pictures from?

4

they’re from http://mobile-augmented-reality.blogspot.com/2009/03/transformation-matrices-between-opengl.html

5

Thanks Ivkoni - been searching for this for a while now. I think UT really ought to have stuff like this in the manual, I shouldn’t have to “magically know” open GL naming conventions in order to understand CG. I haven’t needed to know anything else about open GL up till now, thankfully I’ve already forgotten it again thanks to my browsers’ bookmark feature :).