Rather then have the modifier calculate ORIGINDEX weather its needed or not (incorrect if it wasn't the first modifier on the stack),
create ORIGINDEX layer initially if any of the modifiers use it.
This way hook also works after Mirror and Screw modifiers which have the ORIGINDEX layer copied implicitly with DM_copy_vert_data().
This wasn't possible to check for before because this flag was always enabled so it would be passed to DM_set_only_copy().
Now just add the flag whenever calling DM_set_only_copy().
When there are 2+ consecutive deform modifiers, the second modifier was getting incorrect normals, this only showed up for the displace modifier since its the only deform modifier that uses vertex normals.
It would have been easy to fix this by always calculating normals on deform modifiers, but slow.
To fix this I added a function to check if a deform modifier needs normals, so the normal calculation function only runs if there are 2 modifiers in a row and the second uses normals.
a bit arbitrary but with most cases where solidify is used in durian we get UV texture stretching since there is no way to access the newly created size faces this gives us a way to switch out the material on the rim.
patch by Ben Batt (artificer)
Updated patch for 6 or so modifiers added since the patch was written.
- tested with CMake and SCons
- fixed one error were flags were being added to the fluids type.
- remove BKE_simple_deform.h, simple_deform.c, move functions into MOD_simpledeform.c since there were problems with circular deps.
- moved some fluid and boolean functions used by modifiers too.
