Rotation in model space and rotation in world space

Transform the vertices of the model in the vertex shader , Then follow the teacher's train of thought , The pointer of the following model should follow x Axis rotation ,unity Middle is left-handed coordinates , So its z Axis up ,y Axis right

                void Rotation(float mask, inout float3 vertex, float offset, float angle) {
                    vertex.y -= offset * mask;  // Translate the clock with mask 
                    float radx = radians(angle * mask);
                    float sinx, cosx = 0;
                    sincos(radx, sinx, cosx);
                    vertex.yz = float2(vertex.y * cosx - vertex.z * sinx, vertex.y * sinx + vertex.z * cosx);  
                    vertex.y += offset * mask;
                }
                void ClockRotation(float3 color , inout float3 vertex ) {
                    Rotation( color.r,   vertex, _MoveOffect,  _HourAngle);
                    Rotation( color.g,   vertex, _MoveOffect,  _MinuteAngle);
                    Rotation( color.b,   vertex, _MoveOffect,  _SecondAngle);
                }
                //  Input structure >>> The vertices Shader>>> Output structure 
                VertexOutput vert(VertexInput v) {
                    VertexOutput o = (VertexOutput)0;               
                    // Perform vertex transformation on the time needle 
                    ClockRotation(v.color.rgb, v.vertex.xyz);

}

Later, I found that the effect picture is ：

  It can be clearly seen around z The shaft is turning , instead of x Axis

  Later, it was found that it was in Transform It's adjusted inside y Rotating shaft of shaft , The vertex coordinate is the coordinate in model space , At the beginning, by default, the coordinates of model space and time space are consistent , Instead, it revolves around x The shaft rotates . However, the coordinates of the model in world space are discussed later y Axis 90 Degree rotation , So that the coordinates in the model space also follow y Axis progress 90 Degrees of rotation , This leads to the effect that the pointer surrounds z Axis rotation .

In this case, it is best not to transform the model in space , First deal with the vertex in the existing situation, and then convert its world space .

                void Rotation( float mask, inout float3 vertex, float offset, float angle ) {
                    vertex.y -= offset * mask;  // Translate the clock with mask 
                    float radz = radians(angle * mask);
                    float sinz, cosz = 0;
                    sincos(radz, sinz, cosz);
                    // At present, the vertex is still the vertex data in object space , There is no vertex data converted to world space , So the coordinate system used is still the object coordinate system , The coordinate system of the component is the coordinate system in world space , At the beginning, by default, the coordinate system in object space is the same as that in world space , But it will be different if we change again 
                    // Here we should pay attention to , You need to initialize all the rotation parameters of the model to 0, Then use the current code to adjust the parameters , Finally, change the overall rotation of the model 
                    vertex.xy = float2(vertex.x * cosz - vertex.y * sinz, vertex.x * sinz + vertex.y * cosz);   // The order of rotation parameter adjustment is ： The code rotates using the original default coordinate system , Then rotate the model according to the components , Because when the component rotates, the spatial coordinate axis of the object itself will also be rotated accordingly 
                    vertex.y += offset * mask;
                }