This repository has been archived on 2023-10-09. You can view files and clone it. You cannot open issues or pull requests or push a commit.
Files
blender-archive/source/blender/blenkernel/BKE_multires.h
Hans Goudey 16fbadde36 Mesh: Replace MLoop struct with generic attributes
Implements #102359.

Split the `MLoop` struct into two separate integer arrays called
`corner_verts` and `corner_edges`, referring to the vertex each corner
is attached to and the next edge around the face at each corner. These
arrays can be sliced to give access to the edges or vertices in a face.
Then they are often referred to as "poly_verts" or "poly_edges".

The main benefits are halving the necessary memory bandwidth when only
one array is used and simplifications from using regular integer indices
instead of a special-purpose struct.

The commit also starts a renaming from "loop" to "corner" in mesh code.

Like the other mesh struct of array refactors, forward compatibility is
kept by writing files with the older format. This will be done until 4.0
to ease the transition process.

Looking at a small portion of the patch should give a good impression
for the rest of the changes. I tried to make the changes as small as
possible so it's easy to tell the correctness from the diff. Though I
found Blender developers have been very inventive over the last decade
when finding different ways to loop over the corners in a face.

For performance, nearly every piece of code that deals with `Mesh` is
slightly impacted. Any algorithm that is memory bottle-necked should
see an improvement. For example, here is a comparison of interpolating
a vertex float attribute to face corners (Ryzen 3700x):

**Before** (Average: 3.7 ms, Min: 3.4 ms)
```
threading::parallel_for(loops.index_range(), 4096, [&](IndexRange range) {
  for (const int64_t i : range) {
    dst[i] = src[loops[i].v];
  }
});
```

**After** (Average: 2.9 ms, Min: 2.6 ms)
```
array_utils::gather(src, corner_verts, dst);
```

That's an improvement of 28% to the average timings, and it's also a
simplification, since an index-based routine can be used instead.
For more examples using the new arrays, see the design task.

Pull Request: blender/blender#104424
2023-03-20 15:55:13 +01:00

252 lines
10 KiB
C++

/* SPDX-License-Identifier: GPL-2.0-or-later
* Copyright 2007 by Nicholas Bishop. All rights reserved. */
#pragma once
/** \file
* \ingroup bke
*/
#include "BKE_subsurf.h"
#include "BLI_utildefines.h"
#ifdef __cplusplus
extern "C" {
#endif
struct Depsgraph;
struct DerivedMesh;
struct MDisps;
struct Mesh;
struct ModifierData;
struct MultiresModifierData;
struct Object;
struct Scene;
struct SubdivCCG;
struct MLoopTri;
struct MPoly;
/**
* Delete mesh mdisps and grid paint masks.
*/
void multires_customdata_delete(struct Mesh *me);
void multires_set_tot_level(struct Object *ob, struct MultiresModifierData *mmd, int lvl);
void multires_mark_as_modified(struct Depsgraph *depsgraph,
struct Object *object,
enum MultiresModifiedFlags flags);
void multires_flush_sculpt_updates(struct Object *object);
void multires_force_sculpt_rebuild(struct Object *object);
void multires_force_external_reload(struct Object *object);
/* internal, only called in subsurf_ccg.cc */
void multires_modifier_update_mdisps(struct DerivedMesh *dm, struct Scene *scene);
void multires_modifier_update_hidden(struct DerivedMesh *dm);
/**
* Reset the multi-res levels to match the number of mdisps.
*/
void multiresModifier_set_levels_from_disps(struct MultiresModifierData *mmd, struct Object *ob);
typedef enum MultiresFlags {
MULTIRES_USE_LOCAL_MMD = 1,
MULTIRES_USE_RENDER_PARAMS = 2,
MULTIRES_ALLOC_PAINT_MASK = 4,
MULTIRES_IGNORE_SIMPLIFY = 8,
} MultiresFlags;
ENUM_OPERATORS(MultiresFlags, MULTIRES_IGNORE_SIMPLIFY);
struct DerivedMesh *multires_make_derived_from_derived(struct DerivedMesh *dm,
struct MultiresModifierData *mmd,
struct Scene *scene,
struct Object *ob,
MultiresFlags flags);
struct MultiresModifierData *find_multires_modifier_before(struct Scene *scene,
struct ModifierData *lastmd);
/**
* used for applying scale on mdisps layer and syncing subdivide levels when joining objects.
* \param use_first: return first multi-res modifier if all multi-res'es are disabled.
*/
struct MultiresModifierData *get_multires_modifier(struct Scene *scene,
struct Object *ob,
bool use_first);
int multires_get_level(const struct Scene *scene,
const struct Object *ob,
const struct MultiresModifierData *mmd,
bool render,
bool ignore_simplify);
/**
* Creates mesh with multi-res modifier applied on current object's deform mesh.
*/
struct Mesh *BKE_multires_create_mesh(struct Depsgraph *depsgraph,
struct Object *object,
struct MultiresModifierData *mmd);
/**
* Get coordinates of a deformed base mesh which is an input to the given multi-res modifier.
* \note The modifiers will be re-evaluated.
*/
float (*BKE_multires_create_deformed_base_mesh_vert_coords(struct Depsgraph *depsgraph,
struct Object *object,
struct MultiresModifierData *mmd,
int *r_num_deformed_verts))[3];
/**
* \param direction: 1 for delete higher, 0 for lower (not implemented yet).
*/
void multiresModifier_del_levels(struct MultiresModifierData *mmd,
struct Scene *scene,
struct Object *object,
int direction);
void multiresModifier_base_apply(struct Depsgraph *depsgraph,
struct Object *object,
struct MultiresModifierData *mmd);
int multiresModifier_rebuild_subdiv(struct Depsgraph *depsgraph,
struct Object *object,
struct MultiresModifierData *mmd,
int rebuild_limit,
bool switch_view_to_lower_level);
/**
* If `ob_src` and `ob_dst` both have multi-res modifiers,
* synchronize them such that `ob_dst` has the same total number of levels as `ob_src`.
*/
void multiresModifier_sync_levels_ex(struct Object *ob_dst,
struct MultiresModifierData *mmd_src,
struct MultiresModifierData *mmd_dst);
void multires_stitch_grids(struct Object *);
void multiresModifier_scale_disp(struct Depsgraph *depsgraph,
struct Scene *scene,
struct Object *ob);
void multiresModifier_prepare_join(struct Depsgraph *depsgraph,
struct Scene *scene,
struct Object *ob,
struct Object *to_ob);
int multires_mdisp_corners(const struct MDisps *s);
/**
* Update multi-res data after topology changing.
*/
void multires_topology_changed(struct Mesh *me);
/**
* Makes sure data from an external file is fully read.
*
* Since the multi-res data files only contain displacement vectors without knowledge about
* subdivision level some extra work is needed. Namely make is to all displacement grids have
* proper level and number of displacement vectors set.
*/
void multires_ensure_external_read(struct Mesh *mesh, int top_level);
void multiresModifier_ensure_external_read(struct Mesh *mesh,
const struct MultiresModifierData *mmd);
/**** interpolation stuff ****/
/* Adapted from `sculptmode.c` */
void old_mdisps_bilinear(float out[3], float (*disps)[3], int st, float u, float v);
/**
* Find per-corner coordinate with given per-face UV coord.
*/
int mdisp_rot_face_to_crn(
const struct MPoly *poly, int face_side, float u, float v, float *x, float *y);
/* Reshaping, define in multires_reshape.cc */
bool multiresModifier_reshapeFromVertcos(struct Depsgraph *depsgraph,
struct Object *object,
struct MultiresModifierData *mmd,
const float (*vert_coords)[3],
int num_vert_coords);
/**
* Returns truth on success, false otherwise.
*
* This function might fail in cases like source and destination not having
* matched amount of vertices.
*/
bool multiresModifier_reshapeFromObject(struct Depsgraph *depsgraph,
struct MultiresModifierData *mmd,
struct Object *dst,
struct Object *src);
bool multiresModifier_reshapeFromDeformModifier(struct Depsgraph *depsgraph,
struct Object *ob,
struct MultiresModifierData *mmd,
struct ModifierData *deform_md);
bool multiresModifier_reshapeFromCCG(int tot_level,
struct Mesh *coarse_mesh,
struct SubdivCCG *subdiv_ccg);
/* Subdivide multi-res displacement once. */
typedef enum eMultiresSubdivideModeType {
MULTIRES_SUBDIVIDE_CATMULL_CLARK,
MULTIRES_SUBDIVIDE_SIMPLE,
MULTIRES_SUBDIVIDE_LINEAR,
} eMultiresSubdivideModeType;
void multiresModifier_subdivide(struct Object *object,
struct MultiresModifierData *mmd,
eMultiresSubdivideModeType mode);
void multires_subdivide_create_tangent_displacement_linear_grids(struct Object *object,
struct MultiresModifierData *mmd);
/**
* Subdivide displacement to the given level.
* If level is lower than the current top level nothing happens.
*/
void multiresModifier_subdivide_to_level(struct Object *object,
struct MultiresModifierData *mmd,
int top_level,
eMultiresSubdivideModeType mode);
/* Subdivision integration, defined in multires_subdiv.cc */
struct SubdivSettings;
struct SubdivToMeshSettings;
void BKE_multires_subdiv_settings_init(struct SubdivSettings *settings,
const struct MultiresModifierData *mmd);
/* TODO(sergey): Replace this set of boolean flags with bitmask. */
void BKE_multires_subdiv_mesh_settings_init(struct SubdivToMeshSettings *mesh_settings,
const struct Scene *scene,
const struct Object *object,
const struct MultiresModifierData *mmd,
bool use_render_params,
bool ignore_simplify,
bool ignore_control_edges);
/* General helpers. */
/**
* For a given partial derivatives of a PTEX face get tangent matrix for displacement.
*
* Corner needs to be known to properly "rotate" partial derivatives when the
* matrix is being constructed for quad. For non-quad the corner is to be set to 0.
*/
BLI_INLINE void BKE_multires_construct_tangent_matrix(float tangent_matrix[3][3],
const float dPdu[3],
const float dPdv[3],
int corner);
/* Versioning. */
/**
* Convert displacement which is stored for simply-subdivided mesh to a Catmull-Clark
* subdivided mesh.
*/
void multires_do_versions_simple_to_catmull_clark(struct Object *object,
struct MultiresModifierData *mmd);
#ifdef __cplusplus
}
#endif
#include "intern/multires_inline.h"