The issue is due to a dependency cycle which leads to access of data
which is not ready yet.
The dependency cycle was introduced in ada367a0e9.
This change makes it so there is no dependency cycle in the setup from
the report by re-routing dependencies a bit: the light linking now
bypasses the geometry component and is only wired to an operation
related on instancing collection (but not use by a boolean modifier).
Pull Request: https://projects.blender.org/blender/blender/pulls/127143
The depsgraph CoW mechanism is a bit of a misnomer. It creates an
evaluated copy for data-blocks regardless of whether the copy will
actually be written to. The point is to have physical separation between
original and evaluated data. This is in contrast to the commonly used
performance improvement of keeping a user count and copying data
implicitly when it needs to be changed. In Blender code we call this
"implicit sharing" instead. Importantly, the dependency graph has no
idea about the _actual_ CoW behavior in Blender.
Renaming this functionality in the despgraph removes some of the
confusion that comes up when talking about this, and will hopefully
make the depsgraph less confusing to understand initially too. Wording
like "the evaluated copy" (as opposed to the original data-block) has
also become common anyway.
Pull Request: https://projects.blender.org/blender/blender/pulls/118338
Instead of having a set of hardcoded rules in the collection and
object instance collection builder introduce new node on object's
INSTANCING component which is to be hooked up to the node which is
duplicating the object.
Should be no functional changes.
Currently there is no functional changes.
In the future it allows to more easily hook the shading component
to other nodes to ensure the visibility flow.
Note that since the operation is not used by any relation it will
appear disconnected in the graphviz debugger. This is due to the
current behavior of deg_graph_remove_unused_noops().
