loop and increasing memory usage.
Modifiers should never call mesh_get_derived_final or similar, only
use ob->derivedFinal if it exists, if the dependencies are set correct
and there are no cycles, it will be there.
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.
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.
