Blender Git Loki

GPU: Add better support for displacement relinking behavior

Previously displacement relinking was trying to be smart and seems to be
broken in some cases. This fixes all cases by brute force.

We copy the whole branch linked to the displacement socket and tag it
accordingly. Then we only relink the nodes that are not tagged.

Moreover, we bypass bump nodes inside the dispacement trees so that the
resulting bump is the same as cycles.

Fix T66000 EEVEE: Unexpected results when displacement interact with nodegroups