* The old collisions code detected particle collisions by calculating the
collision times analytically from the collision mesh faces. This was
pretty accurate, but didn't support rotating/deforming faces at all, as
the equations for these quickly become quite nasty.
* The new code uses a simple "distance to plane/edge/vert" function and
iterates this with the Newton-Rhapson method to find the closest particle
distance during a simulation step.
* The advantage in this is that the collision object can now move, rotate,
scale or even deform freely and collisions are still detected reliably.
* For some extreme movements the calculation errors could stack up so much
that the detection fails, but this can be easily fixed by increasing the
particle size or simulation substeps.
* As a side note the algorithm doesn't really do point particles anymore,
but uses a very small radius as the particle size when "size deflect" isn't
selected.
* I've also updated the collision response code a bit, so now the particles
shouldn't leak even from tight corners.
All in all the collisions code is now much cleaner and more robust than before!
most local modifier,GPU,ImBuf and Interface functions are now static.
also fixed an error were the fluid modifier definition and the header didnt have the same number of args.
Used a crazyspace approach (like in edit mode), but only modifiers with
deformMatricies are allowed atm (currently shapekeys and armature modifiers only).
All the rest modifiers had an warning message that they aren't applied because
of sculpt mode. Deformation of multires is also unsupported.
With all this restictions users will always see the actual "layer" (or maybe
mesh state would be more correct word) they are sculpting on.
Internal changes:
- All modifiers could have deformMatricies callback (the same as deformMatriciesEM but
for non-edit mode usage)
- Added function to build crazyspace for sculpting (sculpt_get_deform_matrices), but it
could be generalized for usage in other painting modes (particle edit mode, i.e)
Todo:
- Implement crazyspace correction to support all kinds of deformation modifiers
- Maybe deformation of multires isn't so difficult?
- And maybe we could avoid extra bad-level-stub for ED_sculpt_modifiers_changed
without code duplicating?
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.
* Fractional frames support has been changed to use a new var, scene->r.subframe.
This is a 0.0-1.0 float representing a subframe interval, used in generating a final float
frame number to evaluate animation system etc.
* Changed frame_to_float() and some instances of bsystem_time() into a convenience function:
float BKE_curframe(scene) which retrieves the floating point current frame, after subframe
and frame length corrections.
* Removed blur_offs and field_offs globals. These are now stored in render, used to
generate a scene->r.subframe before render database processing.
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.
