Files
test/source/blender/blenkernel/BKE_mesh_remap.hh
Hans Goudey 89e3ba4e25 Mesh: Replace auto smooth with node group
Design task: #93551

This PR replaces the auto smooth option with a geometry nodes modifier
that sets the sharp edge attribute. This solves a fair number of long-
standing problems related to auto smooth, simplifies the process of
normal computation, and allows Blender to automatically choose between
face, vertex, and face corner normals based on the sharp edge and face
attributes.

Versioning adds a geometry node group to objects with meshes that had
auto-smooth enabled. The modifier can be applied, which also improves
performance.

Auto smooth is now unnecessary to get a combination of sharp and smooth
edges. In general workflows are changed a bit. Separate procedural and
destructive workflows are available. Custom normals can be used
immediately without turning on the removed auto smooth option.

**Procedural**

The node group asset "Smooth by Angle" is the main way to set sharp
normals based on the edge angle. It can be accessed directly in the add
modifier menu. Of course the modifier can be reordered, muted, or
applied like any other, or changed internally like any geometry nodes
modifier.

**Destructive**
Often the sharp edges don't need to be dynamic. This can give better
performance since edge angles don't need to be recalculated. In edit
mode the two operators "Select Sharp Edges" and "Mark Sharp" can be
used. In other modes, the "Shade Smooth by Angle" controls the edge
sharpness directly.

### Breaking API Changes
- `use_auto_smooth` is removed. Face corner normals are now used
  automatically   if there are mixed smooth vs. not smooth tags. Meshes
  now always use custom normals if they exist.
- In Cycles, the lack of the separate auto smooth state makes normals look
  triangulated when all faces are shaded smooth.
- `auto_smooth_angle` is removed. Replaced by a modifier (or operator)
  controlling the sharp edge attribute. This means the mesh itself
  (without an object) doesn't know anything about automatically smoothing
  by angle anymore.
- `create_normals_split`, `calc_normals_split`, and `free_normals_split`
  are removed, and are replaced by the simpler `Mesh.corner_normals`
  collection property. Since it gives access to the normals cache, it
  is automatically updated when relevant data changes.

Addons are updated here: https://projects.blender.org/blender/blender-addons/pulls/104609

### Tests
- `geo_node_curves_test_deform_curves_on_surface` has slightly different
   results because face corner normals are used instead of interpolated
   vertex normals.
- `bf_wavefront_obj_tests` has different export results for one file
  which mixed sharp and smooth faces without turning on auto smooth.
- `cycles_mesh_cpu` has one object which is completely flat shaded.
  Previously every edge was split before rendering, now it looks triangulated.

Pull Request: https://projects.blender.org/blender/blender/pulls/108014
2023-10-20 16:54:08 +02:00

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9.9 KiB
C++

/* SPDX-FileCopyrightText: 2023 Blender Authors
*
* SPDX-License-Identifier: GPL-2.0-or-later */
#pragma once
/** \file
* \ingroup bke
*/
#include "BLI_math_matrix.h"
#include "BLI_math_rotation.h"
#include "BLI_math_vector_types.hh"
#include "BLI_offset_indices.hh"
#include "BKE_mesh_mapping.hh"
struct CustomData;
struct CustomData_MeshMasks;
struct MemArena;
struct Mesh;
/* Generic ways to map some geometry elements from a source mesh to a destination one. */
struct MeshPairRemapItem {
int sources_num;
int *indices_src; /* NULL if no source found. */
float *weights_src; /* NULL if no source found, else, always normalized! */
/* UNUSED (at the moment). */
// float hit_dist; /* FLT_MAX if irrelevant or no source found. */
int island; /* For loops only. */
};
/* All mapping computing func return this. */
struct MeshPairRemap {
int items_num;
MeshPairRemapItem *items; /* Array, one item per destination element. */
MemArena *mem; /* memory arena, internal use only. */
};
/* Helpers! */
void BKE_mesh_remap_init(MeshPairRemap *map, int items_num);
void BKE_mesh_remap_free(MeshPairRemap *map);
void BKE_mesh_remap_item_define_invalid(MeshPairRemap *map, int index);
/* TODO:
* Add other 'from/to' mapping sources, like e.g. using a UVMap, etc.
* https://blenderartists.org/t/619105
*
* We could also use similar topology mappings inside a same mesh
* (cf. Campbell's 'select face islands from similar topology' WIP work).
* Also, users will have to check, whether we can get rid of some modes here,
* not sure all will be useful!
*/
enum {
MREMAP_USE_VERT = 1 << 4,
MREMAP_USE_EDGE = 1 << 5,
MREMAP_USE_LOOP = 1 << 6,
MREMAP_USE_POLY = 1 << 7,
MREMAP_USE_NEAREST = 1 << 8,
MREMAP_USE_NORPROJ = 1 << 9,
MREMAP_USE_INTERP = 1 << 10,
MREMAP_USE_NORMAL = 1 << 11,
/* ***** Target's vertices ***** */
MREMAP_MODE_VERT = 1 << 24,
/* Nearest source vert. */
MREMAP_MODE_VERT_NEAREST = MREMAP_MODE_VERT | MREMAP_USE_VERT | MREMAP_USE_NEAREST,
/* Nearest vertex of nearest edge. */
MREMAP_MODE_VERT_EDGE_NEAREST = MREMAP_MODE_VERT | MREMAP_USE_EDGE | MREMAP_USE_NEAREST,
/* This one uses two verts of selected edge (weighted interpolation). */
/* Nearest point on nearest edge. */
MREMAP_MODE_VERT_EDGEINTERP_NEAREST = MREMAP_MODE_VERT | MREMAP_USE_EDGE | MREMAP_USE_NEAREST |
MREMAP_USE_INTERP,
/* Nearest vertex of nearest face. */
MREMAP_MODE_VERT_FACE_NEAREST = MREMAP_MODE_VERT | MREMAP_USE_POLY | MREMAP_USE_NEAREST,
/* Those two use all verts of selected face (weighted interpolation). */
/* Nearest point on nearest face. */
MREMAP_MODE_VERT_POLYINTERP_NEAREST = MREMAP_MODE_VERT | MREMAP_USE_POLY | MREMAP_USE_NEAREST |
MREMAP_USE_INTERP,
/* Point on nearest face hit by ray from target vertex's normal. */
MREMAP_MODE_VERT_POLYINTERP_VNORPROJ = MREMAP_MODE_VERT | MREMAP_USE_POLY | MREMAP_USE_NORPROJ |
MREMAP_USE_INTERP,
/* ***** Target's edges ***** */
MREMAP_MODE_EDGE = 1 << 25,
/* Source edge which both vertices are nearest of destination ones. */
MREMAP_MODE_EDGE_VERT_NEAREST = MREMAP_MODE_EDGE | MREMAP_USE_VERT | MREMAP_USE_NEAREST,
/* Nearest source edge (using mid-point). */
MREMAP_MODE_EDGE_NEAREST = MREMAP_MODE_EDGE | MREMAP_USE_EDGE | MREMAP_USE_NEAREST,
/* Nearest edge of nearest face (using mid-point). */
MREMAP_MODE_EDGE_POLY_NEAREST = MREMAP_MODE_EDGE | MREMAP_USE_POLY | MREMAP_USE_NEAREST,
/* Cast a set of rays from along destination edge,
* interpolating its vertices' normals, and use hit source edges. */
MREMAP_MODE_EDGE_EDGEINTERP_VNORPROJ = MREMAP_MODE_EDGE | MREMAP_USE_VERT | MREMAP_USE_NORPROJ |
MREMAP_USE_INTERP,
/* ***** Target's loops ***** */
/* NOTE: when islands are given to loop mapping func,
* all loops from the same destination face will always be mapped
* to loops of source faces within a same island, regardless of mapping mode. */
MREMAP_MODE_LOOP = 1 << 26,
/* Best normal-matching loop from nearest vert. */
MREMAP_MODE_LOOP_NEAREST_LOOPNOR = MREMAP_MODE_LOOP | MREMAP_USE_LOOP | MREMAP_USE_VERT |
MREMAP_USE_NEAREST | MREMAP_USE_NORMAL,
/* Loop from best normal-matching face from nearest vert. */
MREMAP_MODE_LOOP_NEAREST_POLYNOR = MREMAP_MODE_LOOP | MREMAP_USE_POLY | MREMAP_USE_VERT |
MREMAP_USE_NEAREST | MREMAP_USE_NORMAL,
/* Loop from nearest vertex of nearest face. */
MREMAP_MODE_LOOP_POLY_NEAREST = MREMAP_MODE_LOOP | MREMAP_USE_POLY | MREMAP_USE_NEAREST,
/* Those two use all verts of selected face (weighted interpolation). */
/* Nearest point on nearest face. */
MREMAP_MODE_LOOP_POLYINTERP_NEAREST = MREMAP_MODE_LOOP | MREMAP_USE_POLY | MREMAP_USE_NEAREST |
MREMAP_USE_INTERP,
/* Point on nearest face hit by ray from target loop's normal. */
MREMAP_MODE_LOOP_POLYINTERP_LNORPROJ = MREMAP_MODE_LOOP | MREMAP_USE_POLY | MREMAP_USE_NORPROJ |
MREMAP_USE_INTERP,
/* ***** Target's faces ***** */
MREMAP_MODE_POLY = 1 << 27,
/* Nearest source face. */
MREMAP_MODE_POLY_NEAREST = MREMAP_MODE_POLY | MREMAP_USE_POLY | MREMAP_USE_NEAREST,
/* Source face from best normal-matching destination face. */
MREMAP_MODE_POLY_NOR = MREMAP_MODE_POLY | MREMAP_USE_POLY | MREMAP_USE_NORMAL,
/* Project destination face onto source mesh using its normal,
* and use interpolation of all intersecting source faces. */
MREMAP_MODE_POLY_POLYINTERP_PNORPROJ = MREMAP_MODE_POLY | MREMAP_USE_POLY | MREMAP_USE_NORPROJ |
MREMAP_USE_INTERP,
/* ***** Same topology, applies to all four elements types. ***** */
MREMAP_MODE_TOPOLOGY = MREMAP_MODE_VERT | MREMAP_MODE_EDGE | MREMAP_MODE_LOOP | MREMAP_MODE_POLY,
};
/**
* Compute a value of the difference between both given meshes.
* The smaller the result, the better the match.
*
* We return the inverse of the average of the inversed
* shortest distance from each dst vertex to src ones.
* In other words, beyond a certain (relatively small) distance, all differences have more or less
* the same weight in final result, which allows to reduce influence of a few high differences,
* in favor of a global good matching.
*/
float BKE_mesh_remap_calc_difference_from_mesh(const SpaceTransform *space_transform,
const float (*vert_positions_dst)[3],
int numverts_dst,
const Mesh *me_src);
/**
* Set r_space_transform so that best bbox of dst matches best bbox of src.
*/
void BKE_mesh_remap_find_best_match_from_mesh(const float (*vert_positions_dst)[3],
int numverts_dst,
const Mesh *me_src,
SpaceTransform *r_space_transform);
void BKE_mesh_remap_calc_verts_from_mesh(int mode,
const SpaceTransform *space_transform,
float max_dist,
float ray_radius,
const float (*vert_positions_dst)[3],
int numverts_dst,
const Mesh *me_src,
Mesh *me_dst,
MeshPairRemap *r_map);
void BKE_mesh_remap_calc_edges_from_mesh(int mode,
const SpaceTransform *space_transform,
float max_dist,
float ray_radius,
const float (*vert_positions_dst)[3],
int numverts_dst,
const blender::int2 *edges_dst,
int numedges_dst,
const Mesh *me_src,
Mesh *me_dst,
MeshPairRemap *r_map);
void BKE_mesh_remap_calc_loops_from_mesh(int mode,
const SpaceTransform *space_transform,
float max_dist,
float ray_radius,
const Mesh *mesh_dst,
const float (*vert_positions_dst)[3],
int numverts_dst,
const int *corner_verts_dst,
int numloops_dst,
const blender::OffsetIndices<int> faces_dst,
const Mesh *me_src,
MeshRemapIslandsCalc gen_islands_src,
float islands_precision_src,
MeshPairRemap *r_map);
void BKE_mesh_remap_calc_faces_from_mesh(int mode,
const SpaceTransform *space_transform,
float max_dist,
float ray_radius,
const Mesh *mesh_dst,
const float (*vert_positions_dst)[3],
int numverts_dst,
const int *corner_verts,
const blender::OffsetIndices<int> faces_dst,
const Mesh *me_src,
MeshPairRemap *r_map);