THREE.JS Shadow on opposite side of light

Question

I used THREE.js r49 create 2 cube geometry with a directional light to cast shadow on them and got result as in the following picture.

I noticed that the shadow in t

Answer 1

Yes, this is a known, and long-standing, WebGLRenderer issue.

The problem is that the dot product of the face normal and the light direction is not taken into consideration in the shadow calculation. As a consequence, "shadows show through from the back".

As a work-around, you could have a different material for each face, with only certain materials receiving shadows.

three.js r.71