gaplegth

UNITY_MATRIX_IT_MV[0].xyz = ???
UNITY_MATRIX_IT_MV[1].xyz = Camera Up
UNITY_MATRIX_IT_MV[2].xyz = Camera Forward

float3 forward = -normalize(UNITY_MATRIX_V._m20_m21_m22);
float3 up = normalize(UNITY_MATRIX_V._m10_m11_m12);
float3 right = normalize(UNITY_MATRIX_V._m00_m01_m02);

float3 cameraUp = unity_CameraInvProjection[1].xyz;
float3 camRight = cross(unity_CameraInvProjection[2].xyz, cameraUp);

gaplegth

// Rotation with angle (in radians) and axis
float3x3 AngleAxis3x3(float angle, float3 axis)
{
    float c, s;
    sincos(angle, s, c);

    float t = 1 - c;
    float x = axis.x;
    float y = axis.y;
    float z = axis.z;