Split node with "random" layer selection interacts poorly with multi-prefab Objects node

The Split node uses the same random selection based on the Transition hash value that the Objects node uses to randomly select between multiple prefabs. Depending on the weights of the split and the number of prefabs, you can get a filtering effect where only one of the prefabs is placed.

For example, if we Scatter, then Split into two streams so that the first stream going to an Objects node has a weight of 25% of the total. Then if the Objects node has 4 prefabs defined, you will only ever get the first prefab placed in the world.

A "fix" (but maybe not the best) for the issue is to modify this line in the Split node:

ObjectsModifiers.cs line 326: float randomVal = random.Random(trs.hash);

to
float randomVal = random.Random(trs.hash + 1);