czm_morphTime
An automatic GLSL uniform representing the current morph transition time between
2D/Columbus View and 3D, with 0.0 being 2D or Columbus View and 1.0 being 3D.
Like all automatic uniforms, czm_morphTime does not need to be explicitly declared.
However, it can be explicitly declared when a shader is also used by other applications such
as a third-party authoring tool.
Example
// GLSL declaration uniform float czm_morphTime; // Example vec4 p = czm_columbusViewMorph(position2D, position3D, czm_morphTime);