Combining Two Vertex Shaders?

Unity Engine
1

I am attempting to make a copy of the Standard shader compatible with the Animation Instancing shader (Unity Blog)
The issue is that the Standard Shader (at least my copy of it) looks like this

#pragma shader_feature _NORMALMAP
#pragma shader_feature _ _ALPHATEST_ON _ALPHABLEND_ON _ALPHAPREMULTIPLY_ON
#pragma shader_feature _EMISSION
#pragma shader_feature _METALLICGLOSSMAP
#pragma shader_feature ___ _DETAIL_MULX2
#pragma shader_feature _ _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A
#pragma shader_feature _ _SPECULARHIGHLIGHTS_OFF
#pragma shader_feature _ _GLOSSYREFLECTIONS_OFF
#pragma shader_feature _PARALLAXMAP

#pragma multi_compile_fwdbase
#pragma multi_compile_fog
#pragma multi_compile_instancing

#pragma vertex vertBase
#pragma fragment fragBase
#include "UnityStandardCoreForward.cginc"

and adding

#include "AnimationInstancingBase.cginc"
#pragma vertex vert

to the end did nothing, probably since it already have a #pragma vertex vertBase declaration.
How do I combine the vert function from AnimationInstancingBase.cginc and the vertBase from UnityStandardCoreForward.cginc?
I am hoping for some simple way of doing that, since there are 8 more passes in the StandardShader all using different vertex ‘pragmas’ in different .cginc files

Worst case scenario I am thinking of copying each of the vertex functions to their respective passes and manually figure out a way to insert the skinning functions from AnimationInstancingBase.cginc, but here I am hoping for a easy solution somehow existing

2

It is non-trivial to modify the Standard Shader. Modifying it usually requires making copies of and hand modifying multiple cginc files to include the functionality you’re looking to have. Honestly, if you’re asking the question “how do I merge these two shaders” the answer is going to be outside of your current ability to do so because it requires understanding how all the bits of code link together and in turn where the new code needs to added.

The existing code from that example is designed to be used in a Surface Shader, which is a very different use case than the vertex fragment shader that the Standard shader is. You can create a Surface Shader that uses the Standard shading model and reimplements most if not all of the features of the Standard shader, but honestly you probably don’t want most of them for a skinned mesh. Indeed the default Surface Shader when you create one in the project view uses the Standard shading model. Just using the Standard shading model and adding normal map support is probably 90% of what you’ll need. The example shaders in that project all implement normal maps too, so you can use that as an example, or find a tutorial online which will probably show how to implement that.

3

I guess adding cutout and double sided to the existing shaders is easier than modifying the standard - two sided I have