As noted in T80164, there are quite a few area of Blender where the "Reset to Default Value" operator
in button context menus doesn't work. Modifiers are one of them, because the DNA defaults system was never set up for them.
Also, this should make versioning for modifiers easier. Whenever a new field is added it should be
automatically initialized to the default value.
I have to make some changes in the following modifiers to work around an error with -Wsign-conversion in the macros.
- Solidify Modifier
- Corrective Smooth Modifier
- Screw Modifier
Here are the next steps for future commits:
- Data Transfer Modifier -- Disabled for now, defines for defaults scattered around too many different files (not in DNA
- Cloth Modifier
- Fluid Modifier
- Softbody Modifier
For the last three, I just prefer to handle the special cases by themselves.