Messing with the Sprite Diffuse shader's normals

Hello all,

Can anybody suggest a solution to my problem shown in the video below? I've never programmed a shader before, but I have a best guess and would like to ask for your advice before proceeding with what I expect to be something quite painful for a noob.

I'm thinking I should write a shader that makes 3 passes, each time changing the calculated normal to be facing a different direction, or would that make my sprite way too bright? I seriously have no idea what I'm doing, but I'll teach myself.

I'd really appreciate getting pointed in the right direction, though!

 

Well, I ended up modifying this here line in the Sprite Diffuse shader...

Code (CSharp):

1. void vert (inout appdata_full v, out Input o)
2.         {
3.             #if defined(PIXELSNAP_ON) && !defined(SHADER_API_FLASH)
4.             v.vertex = UnityPixelSnap (v.vertex);
5.             #endif
6.             v.normal = float3(0,0,-1); /// ...changing this into float3(0.5, 1, 0.5)
7.            
8.             UNITY_INITIALIZE_OUTPUT(Input, o);
9.             o.color = v.color * _Color;
10.         }

...and that mostly took care of the shadowy lighting issues when the billboarding sprite oriented itself edgewise to the lighting source.