PHONG shading causing bugs

Hello,

I am working on a scene where I’m lighting the tables, and I’ve noticed strange light behavior on the surface of the tabletop. Parts close to edge of each tabletop appear darkened. I’m attaching a preview with PHONG disabled as well. It seems to be caused by PHONG SHADING.

Does anyone know a method to fix this issue?


what do you mean with “I disabled the phong tag”?, did you try to remove it? otherwise you have some effect on the material it self…
Another question: do you “cloned” something with clone object?

One image has the Phong angle set to 19 degrees, and it obviously darkens the areas near the edges for no apparent reason. The top surface of the desk should have a consistent color. As soon as I set the Phong angle to 0 degrees, the darkening disappears.

This occurs with both cloned and non-cloned objects. Another solution that helped was selecting the edges between the top surface and the rounded edge and using Break Phong Shading.

Try to use the “area Weighted” parameter on the Phong tag if your object has a fillet structure to avoid the “ellipsoid” phong effects (black areas).

I have tried every PHONG SHADING mode, and to my surprise, the best results came from using the UNIFORM mode.