Ideally need to clean and sane and impossible-to-break way of making sure
evaluation context is fully initialized, but that would need some thoughts
and experimentation.
Otherwise we'll have confused dependency graph builder, which wouldn't be able to
build proper graph.
Didn't find a way to avoid world copy here, we can probably escape with some shallow
copy here, but that will currently complicate code a lot.
Ideas to consider here:
- Use shallow copy of existing world after new ID management API is in place.
Downside would be thread safety, kind of nice to have everything local.
- Switch depsgraph away from ID_TAG and do hash lookup or so.
This will slow down depsgraph builder, but will make code more reliable.
Moving the ray_start_local to the new position does not lose as much precision as moving the ray_org_local to the corresponding position.
The problem of inaccuracy is within the functions: `bvhtree_ray_cast_data_precalc` and` fast_ray_nearest_hit`. And not directly in the values of the rays.
Those functions did not use evaluation context.
Also fixed lots of unused variables warnings caused by commented out code which
needs to be ported away from DerivedMesh and to evaluation context.
Note that some little parts of code have been dissabled because eval_ctx
was not available there. This should be resolved once DerivedMesh is
replaced.
The way we use it, UI_PRECISION_FLOAT_MAX is actually + 1 to get total
number of digits, and float only has 7 meaningful digits, so that define
shall be at 6.
GCC seems to detect uninitialized into function calls now, but then isn't
always smart enough to see that it is actually initialized. Disabling this
warning entirely seems a bit too much, so initialize a bit more now.
The remapping code was creating plkaceholders for objects coming from legacy
bases, but since those objects were never created by dependency graph (since
they are supposed to be ignored) the copy on write relations creation was
confused.
Now we do some special trickery to clear legacy bases on copy on write.
Currently RNA doesn't give us a good way of accessing singleton layers,
for now expose as a layer list (skin & paint-pask do this too).
Noted in T47811 that this should be changed.
Those checks are not always helpful, since id remapping doesn't want to
worry about which components to tag for update. Perhaps in the future we
will introduce special flag which would mean "tag everything possible"/
