My object becomes darker during animation I have made this animation:
https://i.imgur.com/qXzYD8o.mp4
Each frame consists of an object that has been generated independently using python. These objects are isosurfaces of a function at different points in time (it is a rabi oscillation for a single electron in a molecule as the molecule moves from a ground to an excited state). The algorithm used to generate the surfaces provides me with the list of vertices, normals, and faces that define the surface.
There are two emission planes, one below and one above the object. The renderer that I am using is Cycles.
I do not understand why some of the objects appear darker. Could it be that the normals are pointing in the wrong direction in those objects? If that is the case, is there a way to ignore the normals?
EDIT: This is a blend file which contains two objects from two sequential frames. One object appears darker than the other:
So, when you generate objects, you made them without normals. I don't want to say, that they have no normals completely, because mesh can't be without normals. What I see, that all normals are rotated in the same vector, so your objects look completely flat:

But what causes the jittering in colors? This vector is different from one object to another. This mean that your object is shaded completely flat as a single plane can be, but each time the plane is rotated in a different angle.
So, how to fix that, depends on your code. I guess you should use update function (update(calc_edges=True)) to update normals, but maybe I'm wrong. I noted, that clearing custom normal data (in &quot;Geometry data&quot; section) force normals to be recalculated:

You might be wondered why if your object shaded flat, you still see some shading in the render? It is because ambient occlusion still have effect even without proper normals