shrinkwrap.c

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/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) Blender Foundation.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): Andr Pinto
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include <string.h>
#include <float.h>
#include <math.h>
#include <memory.h>
#include <stdio.h>
#include <time.h>
#include <assert.h>

#include "DNA_object_types.h"
#include "DNA_modifier_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_mesh_types.h"
#include "DNA_scene_types.h"

#include "BLI_editVert.h"
#include "BLI_math.h"
#include "BLI_utildefines.h"

#include "BKE_shrinkwrap.h"
#include "BKE_DerivedMesh.h"
#include "BKE_lattice.h"

#include "BKE_deform.h"
#include "BKE_mesh.h"
#include "BKE_subsurf.h"

/* Util macros */
#define OUT_OF_MEMORY() ((void)printf("Shrinkwrap: Out of memory\n"))

/* Benchmark macros */
#if !defined(_WIN32) && 0

#include <sys/time.h>

#define BENCH(a)    \
    do {            \
        double _t1, _t2;                \
        struct timeval _tstart, _tend;  \
        clock_t _clock_init = clock();  \
        gettimeofday ( &_tstart, NULL); \
        (a);                            \
        gettimeofday ( &_tend, NULL);   \
        _t1 = ( double ) _tstart.tv_sec + ( double ) _tstart.tv_usec/ ( 1000*1000 );    \
        _t2 = ( double )   _tend.tv_sec + ( double )   _tend.tv_usec/ ( 1000*1000 );    \
        printf("%s: %fs (real) %fs (cpu)\n", #a, _t2-_t1, (float)(clock()-_clock_init)/CLOCKS_PER_SEC);\
    } while(0)

#else

#define BENCH(a)    (a)

#endif

typedef void ( *Shrinkwrap_ForeachVertexCallback) (DerivedMesh *target, float *co, float *normal);

/* get derived mesh */
//TODO is anyfunction that does this? returning the derivedFinal witouth we caring if its in edit mode or not?
DerivedMesh *object_get_derived_final(Object *ob)
{
    Mesh *me= ob->data;
    EditMesh *em = BKE_mesh_get_editmesh(me);

    if(em) {
        DerivedMesh *dm = em->derivedFinal;
        BKE_mesh_end_editmesh(me, em);
        return dm;
    }

    return ob->derivedFinal;
}

/* Space transform */
void space_transform_from_matrixs(SpaceTransform *data, float local[4][4], float target[4][4])
{
    float itarget[4][4];
    invert_m4_m4(itarget, target);
    mul_serie_m4(data->local2target, itarget, local, NULL, NULL, NULL, NULL, NULL, NULL);
    invert_m4_m4(data->target2local, data->local2target);
}

void space_transform_apply(const SpaceTransform *data, float *co)
{
    mul_v3_m4v3(co, ((SpaceTransform*)data)->local2target, co);
}

void space_transform_invert(const SpaceTransform *data, float *co)
{
    mul_v3_m4v3(co, ((SpaceTransform*)data)->target2local, co);
}

static void space_transform_apply_normal(const SpaceTransform *data, float *no)
{
    mul_mat3_m4_v3( ((SpaceTransform*)data)->local2target, no);
    normalize_v3(no); // TODO: could we just determine de scale value from the matrix?
}

static void space_transform_invert_normal(const SpaceTransform *data, float *no)
{
    mul_mat3_m4_v3(((SpaceTransform*)data)->target2local, no);
    normalize_v3(no); // TODO: could we just determine de scale value from the matrix?
}

/*
 * Shrinkwrap to the nearest vertex
 *
 * it builds a kdtree of vertexs we can attach to and then
 * for each vertex performs a nearest vertex search on the tree
 */
static void shrinkwrap_calc_nearest_vertex(ShrinkwrapCalcData *calc)
{
    int i;

    BVHTreeFromMesh treeData = NULL_BVHTreeFromMesh;
    BVHTreeNearest  nearest  = NULL_BVHTreeNearest;


    BENCH(bvhtree_from_mesh_verts(&treeData, calc->target, 0.0, 2, 6));
    if(treeData.tree == NULL)
    {
        OUT_OF_MEMORY();
        return;
    }

    //Setup nearest
    nearest.index = -1;
    nearest.dist = FLT_MAX;
#ifndef __APPLE__
#pragma omp parallel for default(none) private(i) firstprivate(nearest) shared(treeData,calc) schedule(static)
#endif
    for(i = 0; i<calc->numVerts; ++i)
    {
        float *co = calc->vertexCos[i];
        float tmp_co[3];
        float weight = defvert_array_find_weight_safe(calc->dvert, i, calc->vgroup);
        if(weight == 0.0f) continue;


        //Convert the vertex to tree coordinates
        if(calc->vert) {
            copy_v3_v3(tmp_co, calc->vert[i].co);
        }
        else {
            copy_v3_v3(tmp_co, co);
        }
        space_transform_apply(&calc->local2target, tmp_co);

        //Use local proximity heuristics (to reduce the nearest search)
        //
        //If we already had an hit before.. we assume this vertex is going to have a close hit to that other vertex
        //so we can initiate the "nearest.dist" with the expected value to that last hit.
        //This will lead in prunning of the search tree.
        if(nearest.index != -1)
            nearest.dist = len_squared_v3v3(tmp_co, nearest.co);
        else
            nearest.dist = FLT_MAX;

        BLI_bvhtree_find_nearest(treeData.tree, tmp_co, &nearest, treeData.nearest_callback, &treeData);


        //Found the nearest vertex
        if(nearest.index != -1)
        {
            //Adjusting the vertex weight, so that after interpolating it keeps a certain distance from the nearest position
            float dist = sasqrt(nearest.dist);
            if(dist > FLT_EPSILON) weight *= (dist - calc->keepDist)/dist;

            //Convert the coordinates back to mesh coordinates
            copy_v3_v3(tmp_co, nearest.co);
            space_transform_invert(&calc->local2target, tmp_co);

            interp_v3_v3v3(co, co, tmp_co, weight); //linear interpolation
        }
    }

    free_bvhtree_from_mesh(&treeData);
}

/*
 * This function raycast a single vertex and updates the hit if the "hit" is considered valid.
 * Returns TRUE if "hit" was updated.
 * Opts control whether an hit is valid or not
 * Supported options are:
 *  MOD_SHRINKWRAP_CULL_TARGET_FRONTFACE (front faces hits are ignored)
 *  MOD_SHRINKWRAP_CULL_TARGET_BACKFACE (back faces hits are ignored)
 */
int normal_projection_project_vertex(char options, const float *vert, const float *dir, const SpaceTransform *transf, BVHTree *tree, BVHTreeRayHit *hit, BVHTree_RayCastCallback callback, void *userdata)
{
    float tmp_co[3], tmp_no[3];
    const float *co, *no;
    BVHTreeRayHit hit_tmp;

    //Copy from hit (we need to convert hit rays from one space coordinates to the other
    memcpy( &hit_tmp, hit, sizeof(hit_tmp) );

    //Apply space transform (TODO readjust dist)
    if(transf)
    {
        copy_v3_v3( tmp_co, vert );
        space_transform_apply( transf, tmp_co );
        co = tmp_co;

        copy_v3_v3( tmp_no, dir );
        space_transform_apply_normal( transf, tmp_no );
        no = tmp_no;

        hit_tmp.dist *= mat4_to_scale( ((SpaceTransform*)transf)->local2target );
    }
    else
    {
        co = vert;
        no = dir;
    }

    hit_tmp.index = -1;

    BLI_bvhtree_ray_cast(tree, co, no, 0.0f, &hit_tmp, callback, userdata);

    if(hit_tmp.index != -1) {
        /* invert the normal first so face culling works on rotated objects */
        if(transf) {
            space_transform_invert_normal(transf, hit_tmp.no);
        }

        if (options & (MOD_SHRINKWRAP_CULL_TARGET_FRONTFACE|MOD_SHRINKWRAP_CULL_TARGET_BACKFACE)) {
            /* apply backface */
            const float dot= dot_v3v3(dir, hit_tmp.no);
            if( ((options & MOD_SHRINKWRAP_CULL_TARGET_FRONTFACE) && dot <= 0.0f) ||
                ((options & MOD_SHRINKWRAP_CULL_TARGET_BACKFACE) && dot >= 0.0f)
            ) {
                return FALSE; /* Ignore hit */
            }
        }

        if(transf) {
            /* Inverting space transform (TODO make coeherent with the initial dist readjust) */
            space_transform_invert(transf, hit_tmp.co);
            hit_tmp.dist = len_v3v3((float *)vert, hit_tmp.co);
        }

        memcpy(hit, &hit_tmp, sizeof(hit_tmp) );
        return TRUE;
    }
    return FALSE;
}


static void shrinkwrap_calc_normal_projection(ShrinkwrapCalcData *calc)
{
    int i;

    //Options about projection direction
    const char use_normal   = calc->smd->shrinkOpts;
    float proj_axis[3]      = {0.0f, 0.0f, 0.0f};

    //Raycast and tree stuff
    BVHTreeRayHit hit;
    BVHTreeFromMesh treeData= NULL_BVHTreeFromMesh;

    //auxiliar target
    DerivedMesh *auxMesh    = NULL;
    BVHTreeFromMesh auxData = NULL_BVHTreeFromMesh;
    SpaceTransform local2aux;

    //If the user doesn't allows to project in any direction of projection axis
    //then theres nothing todo.
    if((use_normal & (MOD_SHRINKWRAP_PROJECT_ALLOW_POS_DIR | MOD_SHRINKWRAP_PROJECT_ALLOW_NEG_DIR)) == 0)
        return;


    //Prepare data to retrieve the direction in which we should project each vertex
    if(calc->smd->projAxis == MOD_SHRINKWRAP_PROJECT_OVER_NORMAL)
    {
        if(calc->vert == NULL) return;
    }
    else
    {
        //The code supports any axis that is a combination of X,Y,Z
        //altought currently UI only allows to set the 3 diferent axis
        if(calc->smd->projAxis & MOD_SHRINKWRAP_PROJECT_OVER_X_AXIS) proj_axis[0] = 1.0f;
        if(calc->smd->projAxis & MOD_SHRINKWRAP_PROJECT_OVER_Y_AXIS) proj_axis[1] = 1.0f;
        if(calc->smd->projAxis & MOD_SHRINKWRAP_PROJECT_OVER_Z_AXIS) proj_axis[2] = 1.0f;

        normalize_v3(proj_axis);

        //Invalid projection direction
        if(dot_v3v3(proj_axis, proj_axis) < FLT_EPSILON)
            return; 
    }

    if(calc->smd->auxTarget)
    {
        auxMesh = object_get_derived_final(calc->smd->auxTarget);
        if(!auxMesh)
            return;
        space_transform_setup( &local2aux, calc->ob, calc->smd->auxTarget);
    }

    //After sucessufuly build the trees, start projection vertexs
    if( bvhtree_from_mesh_faces(&treeData, calc->target, 0.0, 4, 6)
    &&  (auxMesh == NULL || bvhtree_from_mesh_faces(&auxData, auxMesh, 0.0, 4, 6)))
    {

#ifndef __APPLE__
#pragma omp parallel for private(i,hit) schedule(static)
#endif
        for(i = 0; i<calc->numVerts; ++i)
        {
            float *co = calc->vertexCos[i];
            float tmp_co[3], tmp_no[3];
            float weight = defvert_array_find_weight_safe(calc->dvert, i, calc->vgroup);

            if(weight == 0.0f) continue;

            if(calc->vert)
            {
                /* calc->vert contains verts from derivedMesh  */
                /* this coordinated are deformed by vertexCos only for normal projection (to get correct normals) */
                /* for other cases calc->varts contains undeformed coordinates and vertexCos should be used */
                if(calc->smd->projAxis == MOD_SHRINKWRAP_PROJECT_OVER_NORMAL) {
                    copy_v3_v3(tmp_co, calc->vert[i].co);
                    normal_short_to_float_v3(tmp_no, calc->vert[i].no);
                } else {
                    copy_v3_v3(tmp_co, co);
                    copy_v3_v3(tmp_no, proj_axis);
                }
            }
            else
            {
                copy_v3_v3(tmp_co, co);
                copy_v3_v3(tmp_no, proj_axis);
            }


            hit.index = -1;
            hit.dist = 10000.0f; //TODO: we should use FLT_MAX here, but sweepsphere code isnt prepared for that

            //Project over positive direction of axis
            if(use_normal & MOD_SHRINKWRAP_PROJECT_ALLOW_POS_DIR)
            {

                if(auxData.tree)
                    normal_projection_project_vertex(0, tmp_co, tmp_no, &local2aux, auxData.tree, &hit, auxData.raycast_callback, &auxData);

                normal_projection_project_vertex(calc->smd->shrinkOpts, tmp_co, tmp_no, &calc->local2target, treeData.tree, &hit, treeData.raycast_callback, &treeData);
            }

            //Project over negative direction of axis
            if(use_normal & MOD_SHRINKWRAP_PROJECT_ALLOW_NEG_DIR && hit.index == -1)
            {
                float inv_no[3];
                negate_v3_v3(inv_no, tmp_no);

                if(auxData.tree)
                    normal_projection_project_vertex(0, tmp_co, inv_no, &local2aux, auxData.tree, &hit, auxData.raycast_callback, &auxData);

                normal_projection_project_vertex(calc->smd->shrinkOpts, tmp_co, inv_no, &calc->local2target, treeData.tree, &hit, treeData.raycast_callback, &treeData);
            }


            if(hit.index != -1)
            {
                madd_v3_v3v3fl(hit.co, hit.co, tmp_no, calc->keepDist);
                interp_v3_v3v3(co, co, hit.co, weight);
            }
        }
    }

    //free data structures
    free_bvhtree_from_mesh(&treeData);
    free_bvhtree_from_mesh(&auxData);
}

/*
 * Shrinkwrap moving vertexs to the nearest surface point on the target
 *
 * it builds a BVHTree from the target mesh and then performs a
 * NN matchs for each vertex
 */
static void shrinkwrap_calc_nearest_surface_point(ShrinkwrapCalcData *calc)
{
    int i;

    BVHTreeFromMesh treeData = NULL_BVHTreeFromMesh;
    BVHTreeNearest  nearest  = NULL_BVHTreeNearest;

    //Create a bvh-tree of the given target
    BENCH(bvhtree_from_mesh_faces( &treeData, calc->target, 0.0, 2, 6));
    if(treeData.tree == NULL)
    {
        OUT_OF_MEMORY();
        return;
    }

    //Setup nearest
    nearest.index = -1;
    nearest.dist = FLT_MAX;


    //Find the nearest vertex
#ifndef __APPLE__
#pragma omp parallel for default(none) private(i) firstprivate(nearest) shared(calc,treeData) schedule(static)
#endif
    for(i = 0; i<calc->numVerts; ++i)
    {
        float *co = calc->vertexCos[i];
        float tmp_co[3];
        float weight = defvert_array_find_weight_safe(calc->dvert, i, calc->vgroup);
        if(weight == 0.0f) continue;

        //Convert the vertex to tree coordinates
        if(calc->vert)
        {
            copy_v3_v3(tmp_co, calc->vert[i].co);
        }
        else
        {
            copy_v3_v3(tmp_co, co);
        }
        space_transform_apply(&calc->local2target, tmp_co);

        //Use local proximity heuristics (to reduce the nearest search)
        //
        //If we already had an hit before.. we assume this vertex is going to have a close hit to that other vertex
        //so we can initiate the "nearest.dist" with the expected value to that last hit.
        //This will lead in prunning of the search tree.
        if(nearest.index != -1)
            nearest.dist = len_squared_v3v3(tmp_co, nearest.co);
        else
            nearest.dist = FLT_MAX;

        BLI_bvhtree_find_nearest(treeData.tree, tmp_co, &nearest, treeData.nearest_callback, &treeData);

        //Found the nearest vertex
        if(nearest.index != -1)
        {
            if(calc->smd->shrinkOpts & MOD_SHRINKWRAP_KEEP_ABOVE_SURFACE)
            {
                //Make the vertex stay on the front side of the face
                madd_v3_v3v3fl(tmp_co, nearest.co, nearest.no, calc->keepDist);
            }
            else
            {
                //Adjusting the vertex weight, so that after interpolating it keeps a certain distance from the nearest position
                float dist = sasqrt( nearest.dist );
                if(dist > FLT_EPSILON)
                    interp_v3_v3v3(tmp_co, tmp_co, nearest.co, (dist - calc->keepDist)/dist);   //linear interpolation
                else
                    copy_v3_v3( tmp_co, nearest.co );
            }

            //Convert the coordinates back to mesh coordinates
            space_transform_invert(&calc->local2target, tmp_co);
            interp_v3_v3v3(co, co, tmp_co, weight); //linear interpolation
        }
    }

    free_bvhtree_from_mesh(&treeData);
}

/* Main shrinkwrap function */
void shrinkwrapModifier_deform(ShrinkwrapModifierData *smd, Object *ob, DerivedMesh *dm, float (*vertexCos)[3], int numVerts)
{

    DerivedMesh *ss_mesh    = NULL;
    ShrinkwrapCalcData calc = NULL_ShrinkwrapCalcData;

    //remove loop dependencies on derived meshs (TODO should this be done elsewhere?)
    if(smd->target == ob) smd->target = NULL;
    if(smd->auxTarget == ob) smd->auxTarget = NULL;


    //Configure Shrinkwrap calc data
    calc.smd = smd;
    calc.ob = ob;
    calc.numVerts = numVerts;
    calc.vertexCos = vertexCos;

    //DeformVertex
    calc.vgroup = defgroup_name_index(calc.ob, calc.smd->vgroup_name);
    if(dm)
    {
        calc.dvert = dm->getVertDataArray(dm, CD_MDEFORMVERT);
    }
    else if(calc.ob->type == OB_LATTICE)
    {
        calc.dvert = lattice_get_deform_verts(calc.ob);
    }


    if(smd->target)
    {
        calc.target = object_get_derived_final(smd->target);

        //TODO there might be several "bugs" on non-uniform scales matrixs
        //because it will no longer be nearest surface, not sphere projection
        //because space has been deformed
        space_transform_setup(&calc.local2target, ob, smd->target);

        //TODO: smd->keepDist is in global units.. must change to local
        calc.keepDist = smd->keepDist;
    }



    calc.vgroup = defgroup_name_index(calc.ob, smd->vgroup_name);

    if(dm != NULL && smd->shrinkType == MOD_SHRINKWRAP_PROJECT)
    {
        //Setup arrays to get vertexs positions, normals and deform weights
        calc.vert   = dm->getVertDataArray(dm, CD_MVERT);
        calc.dvert  = dm->getVertDataArray(dm, CD_MDEFORMVERT);

        //Using vertexs positions/normals as if a subsurface was applied 
        if(smd->subsurfLevels)
        {
            SubsurfModifierData ssmd= {{NULL}};
            ssmd.subdivType = ME_CC_SUBSURF;        //catmull clark
            ssmd.levels     = smd->subsurfLevels;   //levels

            ss_mesh = subsurf_make_derived_from_derived(dm, &ssmd, FALSE, NULL, 0, 0, (ob->mode & OB_MODE_EDIT));

            if(ss_mesh)
            {
                calc.vert = ss_mesh->getVertDataArray(ss_mesh, CD_MVERT);
                if(calc.vert)
                {
                    //TRICKY: this code assumes subsurface will have the transformed original vertices
                    //in their original order at the end of the vert array.
                    calc.vert = calc.vert + ss_mesh->getNumVerts(ss_mesh) - dm->getNumVerts(dm);
                }
            }

            //Just to make sure we are not leaving any memory behind
            assert(ssmd.emCache == NULL);
            assert(ssmd.mCache == NULL);
        }
    }

    //Projecting target defined - lets work!
    if(calc.target)
    {
        switch(smd->shrinkType)
        {
            case MOD_SHRINKWRAP_NEAREST_SURFACE:
                BENCH(shrinkwrap_calc_nearest_surface_point(&calc));
            break;

            case MOD_SHRINKWRAP_PROJECT:
                BENCH(shrinkwrap_calc_normal_projection(&calc));
            break;

            case MOD_SHRINKWRAP_NEAREST_VERTEX:
                BENCH(shrinkwrap_calc_nearest_vertex(&calc));
            break;
        }
    }

    //free memory
    if(ss_mesh)
        ss_mesh->release(ss_mesh);
}