Notes:
* Code in rendering and in game engine will still convert
tangents to a tessface representation. Added code that
takes care of tangent layer only, might be removed
when BGE and rendering goes full mlooptri mode.
* Baking should work discovered some dead code while
I was working on the patch, also tangents are broken
when baking from multires (also in master), but those
are separate issues that can be fixed later.
This should fix T45491 as well
Since it was not ensuring dest has valid mdisp data matching new multires modifier subdiv level...
Also, fixed a bug in `multires_subdivide()`, which would crash when trying to
increase from level 0 (aka no subdiv) to > 1 (wrong check, trying to interpolate
when it should not). And added a few sanity checks.
When removing a skin or multires modifier, it skips deletion of the
associated CustomData layer if the object has any other modifiers of
that type. This check has been extended to all objects that use the
object's data.
Similarly, deleting higher multires levels and multires subdivision
will not update the maximum level of any other multires modifiers on
objects that link to the same mesh.
Note that modifier_apply_obdata() doesn't need any changes as it
does not allow applying to multi-user data.
Object joining has also been modified to synchronize multires levels
objects that share a mesh. This is needed because joining can
subdivide or delete levels in order to match the maximum level of the
join-from object to the join-to object.
Fixes bug [#31880] instance multiresolution modifier error.
http://projects.blender.org/tracker/index.php?func=detail&aid=31880&group_id=9&atid=498
Reviewed by Sergey:
http://codereview.appspot.com/6332047/
* Add new CCG function ccgSubSurf_setAllocMask(). Similar to to
ccgSubSurf_setCalcVertexNormals(), it sets whether the CCG elements
have a mask layer and what that layer's offset is. Unlike normals
however, it doesn't change any behavior during CCG calculation; it's
there only to give CCGKey information on the mask.
* Add a new flag to _getSubSurf(), CCG_ALLOC_MASK. If set, space for
an extra layer is allocated, but the number of CCG layers is not set
to include it. This is done because GridPaintMasks are absolute,
rather than being relative to the subdivided output (as MDisp
displacements are), so we skip subdividing paint masks here.
* Add a new flag to subsurf_make_derived_from_derived(),
SUBSURF_ALLOC_PAINT_MASK. This controls whether CCG_ALLOC_MASK is
set for _getSubSurf(). Related, masks are never loaded in during
ss_sync_from_derivedmesh(). After subdivision is finished, if the
alloc mask flag is set, the number of CCG layers is increase to 4
with ccgSubSurf_setNumLayers().
* Add a new flag to multires_make_from_derived(),
MULTIRES_ALLOC_PAINT_MASK. Not all multires functions need paint
mask data (e.g. multiresModifier_base_apply.) This flag is always
set in MOD_multires.c so that subdividing a mesh with a mask updates
properly even when not in sculpt mode.
* Update multiresModifier_disp_run() to apply, calculate, and add mask
elements. It's almost the same as the existing operations with xyz
coordinates, but treats masks as absolute rather than displacements
relative to subdivided values.
* Update multires_customdata_delete to free CD_GRID_PAINT_MASK in
addition to CD_MDISPS.
* Update multires_del_higher() to call the new function
multires_grid_paint_mask_downsample(), which allocates a
lower-resolution paint mask grid and copies values over from the
high-resolution grid.
Changed name to multires_make_derived_from_derived() and parameter
order to be more similar to subsurf_make_derived_from_derived().
Added MultiresFlags enum with flag values to replace the local_mmd and
useRenderParams parameters.
This call is still needed when loading editmesh because some operations
are not creating CD layer for new loops (like crating new face) and
to prevent loosing all sculpted data when running disps correct
displacement maps should be allocated on loading edit mesh.
Renamed the multiresModifier_update() function to
multires_modifier_update_mdisps() and made it visible to subsurf_ccg.c
so it can be called directly. No functional change, just a bit simpler.
- Removed validate() callback for MDisps layer. It wouldn't actually work
correct from CustomData layer and all needed data might be validated from
BMesh interpolation level. Also this callback was never actually used in
BMesh, so can't see why we'll want to have it in structures.
- Removed layrInterp_mdisps callback. Interpolation now happens from
another level (bmesh_interp) and this callback isn't needed anymore.
- Removed all function from multires.c which were used by old interpolation
stuff and seems to be useless for other usages.
- multires_topology_changed is still marked as a TODO, Probably it's not
needed anymore, buy better to keep for now until it'll be 100% clear this
function isn't needed and all needed re-allocations happens in bmesh_interp.
Otherwise, it'll be needed to be ported to new system.
=======================
Added option to baked named "Bake From Multires" which is avaliable for
normals baking and displacement baking.
If this option is enabled, then no additional hi-res meshes and render
structures would be created . This saves plenty of memory and meshes
with millions of faces could be successfully baked in few minutes.
Baking happens from highest level against viewport subdivision level,
so workflow is following:
- Set viewport level to level at which texture would be applied
during final rendering.
- Choose Displacement/Normals baking.
- Enable "Bake From Multires" option.
- You're ready to bake.
Displacement baker had aditional option named "Low Resolution Mesh".
This option is used to set if you want texture for realtime (games)
usage.
Internally it does the following:
- If it's disabled, displacement is calculated from subdivided
viewport level, so texture looks "smooth" (it's how default
baked works).
- If it's enabled, dispalcement is calculated against unsubdivided
viewport levels. This leads to "scales". This isn;t useful for
offline renders much, but very useful for creating game textures.
Special thanks to Morten Mikkelsen (aka sparky) for all mathematics
and other work he've done fr this patch!
Multires interpolation is considerably better
now, though it still has a problem with occasionally
producing little random tangent spikes. Still, it's
far better then it was.
Also fixed a bug in dissolve faces.
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?
This adds the "Apply Base" feature from my gsoc2010 branch.
Apply Base partially applies the modifier, in that the mesh is
reshaped to more closely match the deformed mesh. The upper-level
displacements are recalculated so that the highest multires level
appears unchanged.
Multires does not currently deal well with too large displacements.
An easy-to-reproduce example: create any mesh type, add multires,
subdivide a few times, then use the sculpt grab brush to drag the
entire mesh over a few units. At the highest level, and at level 0,
the mesh looks fine, but all of the intervening levels will have ugly
spikes on them.
This patch doesn't help with situations where you can't modify the
base mesh, but otherwise works around the problem fairly well (albeit
with a heuristic, not an exact solution.)
work correct with sculpting data now.
Joining two triangles could give incorrect sculpting result for
special topologies, but it's that case that can't be nicely handled
with our layers architecture.
Sculpt data shouldn't be lost when making topology changes without
quads<->tris face converison.
General idea:
- Go through all grid points of each corner and convert per-corner
coordiante to per-face cooredinate
- Apply weights and convert new point to per-corner coordinate
- Use bilinear interpolation to get needed displacement vector
Some additional work was necessery:
- Two neighbour corners could have different displacements along common
boundary. multires_mdisp_smooth_bounds() makes displacement "symmetrical"
- Point could change it's corner, so displacement vector should be flipped
in some way. In some cases it's not only flipping, because corner could
be mapped with some rotation. It's not solved for triangular faces yet,
so only z-axis displacement would be interpolated for tris.
More limitations:
- Interpolation will give incorrect result after quad<->triangle
face conversion.
- When face normal was fillped displacement would change it's direction too.
Fix#22018: joining objects with different multires levels loses levesl from the higher multires object
- Synchronyze mulires subdivision level when joining objects
- Apply scale on MDISP layer when applying scale
- Re-calculate MDISP when joining scaled objects
Fixed bug #23657, "Modifiers dosen't work when you select diffrent mesh for object"
Multires modifier now adds empty mdisps if they're missing, rather than displaying a warning
Switching an object's mesh will now check for a multires modifier; if found the modifier's total number of levels are reset to match the mesh's mdisps
Switching the mesh also forces a multires update so that sculpted changes aren't lost
multires modifier if both are in the stack (patch #21965)
This patch also removes limitation of multires reshaping when
destination object has got modifiers after multires modifier.
* Displacement coordinates are now stored differently, as a grid per
face corner. This means there is duplication of coordinates, especially
at low subdivision levels, but the simpler implementation justifies it
I think.
* ToDo: conversion of existing multires files (2.4x or 2.5x), loading them
may even crash now.
* Editmode preservation/interpolation code also has not been updated yet.
* Multires now works on the CCGDerivedMesh grids instead of CDDerivedMesh,
which should be more memory efficient.
* There are still bad memory peaks (if you're using 32bit) when subdividing
or propagating displacements. Though at least there should be no huge
memory blocks allocated, which windows is now to have trouble with.
* Still found some weird spike artifacts at lower multires levels, some also
happening before this commit. Perhaps computation of tangents needs to be
tweaked more.
* Multires modifier now has viewport, sculpt and render levels. Also the
levels have been made consistent with subsurf, previously the same level
of subdivision was one less for multires.
* Both multires and subsurf modifier now can have their subdivision level
set to 0 for no subdivision.
Attempt to make multires updating a little cleaner by
assuming that no update needs to be performed, and only
doing the update when the modified flag is set (either
by sculpting or using some other tool that needs an update.)
