Fix for tangent regression w/ looptri changes

LoopTri changes in 2.76 calculated all tangents as triangles,
this gave different results though in most cases it was hard to notice.

Though no bugs were reported we should keep our tangents compatible with other users of mikktspace.
This commit is contained in:
Campbell Barton 2016-01-20 15:35:51 +11:00
parent a197023439
commit 7e9feac3e0
2 changed files with 353 additions and 37 deletions

View File

@ -2990,6 +2990,9 @@ void mesh_get_mapped_verts_coords(DerivedMesh *dm, float (*r_cos)[3], const int
/** \name Tangent Space Calculation
* \{ */
/* Necessary complexity to handle looptri's as quads for correct tangents */
#define USE_LOOPTRI_DETECT_QUADS
typedef struct {
float (*precomputedFaceNormals)[3];
float (*precomputedLoopNormals)[3];
@ -3002,6 +3005,13 @@ typedef struct {
float (*tangent)[4]; /* destination */
int numTessFaces;
#ifdef USE_LOOPTRI_DETECT_QUADS
/* map from 'fake' face index to looptri,
* quads will point to the first looptri of the quad */
const int *face_as_quad_map;
int num_face_as_quad_map;
#endif
} SGLSLMeshToTangent;
/* interface */
@ -3010,14 +3020,30 @@ typedef struct {
static int dm_ts_GetNumFaces(const SMikkTSpaceContext *pContext)
{
SGLSLMeshToTangent *pMesh = pContext->m_pUserData;
#ifdef USE_LOOPTRI_DETECT_QUADS
return pMesh->num_face_as_quad_map;
#else
return pMesh->numTessFaces;
#endif
}
static int dm_ts_GetNumVertsOfFace(const SMikkTSpaceContext *pContext, const int face_num)
{
//SGLSLMeshToTangent *pMesh = pContext->m_pUserData;
#ifdef USE_LOOPTRI_DETECT_QUADS
SGLSLMeshToTangent *pMesh = pContext->m_pUserData;
if (pMesh->face_as_quad_map) {
const MLoopTri *lt = &pMesh->looptri[pMesh->face_as_quad_map[face_num]];
const MPoly *mp = &pMesh->mpoly[lt->poly];
if (mp->totloop == 4) {
return 4;
}
}
return 3;
#else
UNUSED_VARS(pContext, face_num);
return 3;
#endif
}
static void dm_ts_GetPosition(
@ -3026,8 +3052,30 @@ static void dm_ts_GetPosition(
{
//assert(vert_index >= 0 && vert_index < 4);
SGLSLMeshToTangent *pMesh = pContext->m_pUserData;
const MLoopTri *lt = &pMesh->looptri[face_num];
const float *co = pMesh->mvert[pMesh->mloop[lt->tri[vert_index]].v].co;
const MLoopTri *lt;
int loop_index;
const float *co;
#ifdef USE_LOOPTRI_DETECT_QUADS
if (pMesh->face_as_quad_map) {
lt = &pMesh->looptri[pMesh->face_as_quad_map[face_num]];
const MPoly *mp = &pMesh->mpoly[lt->poly];
if (mp->totloop == 4) {
loop_index = mp->loopstart + vert_index;
goto finally;
}
/* fall through to regular triangle */
}
else {
lt = &pMesh->looptri[face_num];
}
#else
lt = &pMesh->looptri[face_num];
#endif
loop_index = lt->tri[vert_index];
finally:
co = pMesh->mvert[pMesh->mloop[loop_index].v].co;
copy_v3_v3(r_co, co);
}
@ -3037,14 +3085,34 @@ static void dm_ts_GetTextureCoordinate(
{
//assert(vert_index >= 0 && vert_index < 4);
SGLSLMeshToTangent *pMesh = pContext->m_pUserData;
const MLoopTri *lt = &pMesh->looptri[face_num];
const MLoopTri *lt;
int loop_index;
#ifdef USE_LOOPTRI_DETECT_QUADS
if (pMesh->face_as_quad_map) {
lt = &pMesh->looptri[pMesh->face_as_quad_map[face_num]];
const MPoly *mp = &pMesh->mpoly[lt->poly];
if (mp->totloop == 4) {
loop_index = mp->loopstart + vert_index;
goto finally;
}
/* fall through to regular triangle */
}
else {
lt = &pMesh->looptri[face_num];
}
#else
lt = &pMesh->looptri[face_num];
#endif
loop_index = lt->tri[vert_index];
finally:
if (pMesh->mloopuv != NULL) {
const float *uv = pMesh->mloopuv[lt->tri[vert_index]].uv;
const float *uv = pMesh->mloopuv[loop_index].uv;
copy_v2_v2(r_uv, uv);
}
else {
const float *orco = pMesh->orco[pMesh->mloop[lt->tri[vert_index]].v];
const float *orco = pMesh->orco[pMesh->mloop[loop_index].v];
map_to_sphere(&r_uv[0], &r_uv[1], orco[0], orco[1], orco[2]);
}
}
@ -3054,27 +3122,60 @@ static void dm_ts_GetNormal(
const int face_num, const int vert_index)
{
//assert(vert_index >= 0 && vert_index < 4);
SGLSLMeshToTangent *pMesh = pContext->m_pUserData;
const MLoopTri *lt = &pMesh->looptri[face_num];
const bool smoothnormal = (pMesh->mpoly[lt->poly].flag & ME_SMOOTH) != 0;
SGLSLMeshToTangent *pMesh = (SGLSLMeshToTangent *) pContext->m_pUserData;
const MLoopTri *lt;
int loop_index;
if (pMesh->precomputedLoopNormals) {
copy_v3_v3(r_no, pMesh->precomputedLoopNormals[lt->tri[vert_index]]);
#ifdef USE_LOOPTRI_DETECT_QUADS
if (pMesh->face_as_quad_map) {
lt = &pMesh->looptri[pMesh->face_as_quad_map[face_num]];
const MPoly *mp = &pMesh->mpoly[lt->poly];
if (mp->totloop == 4) {
loop_index = mp->loopstart + vert_index;
goto finally;
}
/* fall through to regular triangle */
}
else if (!smoothnormal) { // flat
else {
lt = &pMesh->looptri[face_num];
}
#else
lt = &pMesh->looptri[face_num];
#endif
loop_index = lt->tri[vert_index];
finally:
if (pMesh->precomputedLoopNormals) {
copy_v3_v3(r_no, pMesh->precomputedLoopNormals[loop_index]);
}
else if ((pMesh->mpoly[lt->poly].flag & ME_SMOOTH) == 0) { /* flat */
if (pMesh->precomputedFaceNormals) {
copy_v3_v3(r_no, pMesh->precomputedFaceNormals[lt->poly]);
}
else {
const float *p0 = pMesh->mvert[pMesh->mloop[lt->tri[0]].v].co;
const float *p1 = pMesh->mvert[pMesh->mloop[lt->tri[1]].v].co;
const float *p2 = pMesh->mvert[pMesh->mloop[lt->tri[2]].v].co;
normal_tri_v3(r_no, p0, p1, p2);
#ifdef USE_LOOPTRI_DETECT_QUADS
const MPoly *mp = &pMesh->mpoly[lt->poly];
if (mp->totloop == 4) {
normal_quad_v3(
r_no,
pMesh->mvert[pMesh->mloop[mp->loopstart + 0].v].co,
pMesh->mvert[pMesh->mloop[mp->loopstart + 1].v].co,
pMesh->mvert[pMesh->mloop[mp->loopstart + 2].v].co,
pMesh->mvert[pMesh->mloop[mp->loopstart + 3].v].co);
}
else
#endif
{
normal_tri_v3(
r_no,
pMesh->mvert[pMesh->mloop[lt->tri[0]].v].co,
pMesh->mvert[pMesh->mloop[lt->tri[1]].v].co,
pMesh->mvert[pMesh->mloop[lt->tri[2]].v].co);
}
}
}
else {
const short *no = pMesh->mvert[pMesh->mloop[lt->tri[vert_index]].v].no;
const short *no = pMesh->mvert[pMesh->mloop[loop_index].v].no;
normal_short_to_float_v3(r_no, no);
}
}
@ -3084,9 +3185,32 @@ static void dm_ts_SetTSpace(
const int face_num, const int vert_index)
{
//assert(vert_index >= 0 && vert_index < 4);
SGLSLMeshToTangent *pMesh = pContext->m_pUserData;
const MLoopTri *lt = &pMesh->looptri[face_num];
float *pRes = pMesh->tangent[lt->tri[vert_index]];
SGLSLMeshToTangent *pMesh = (SGLSLMeshToTangent *) pContext->m_pUserData;
const MLoopTri *lt;
int loop_index;
#ifdef USE_LOOPTRI_DETECT_QUADS
if (pMesh->face_as_quad_map) {
lt = &pMesh->looptri[pMesh->face_as_quad_map[face_num]];
const MPoly *mp = &pMesh->mpoly[lt->poly];
if (mp->totloop == 4) {
loop_index = mp->loopstart + vert_index;
goto finally;
}
/* fall through to regular triangle */
}
else {
lt = &pMesh->looptri[face_num];
}
#else
lt = &pMesh->looptri[face_num];
#endif
loop_index = lt->tri[vert_index];
float *pRes;
finally:
pRes = pMesh->tangent[loop_index];
copy_v3_v3(pRes, fvTangent);
pRes[3] = fSign;
}
@ -3133,6 +3257,31 @@ void DM_calc_loop_tangents(DerivedMesh *dm)
DM_add_loop_layer(dm, CD_TANGENT, CD_CALLOC, NULL);
tangent = DM_get_loop_data_layer(dm, CD_TANGENT);
#ifdef USE_LOOPTRI_DETECT_QUADS
int num_face_as_quad_map;
int *face_as_quad_map = NULL;
/* map faces to quads */
if (totface != dm->getNumPolys(dm)) {
/* over alloc, since we dont know how many ngon or quads we have */
/* map fake face index to looptri */
face_as_quad_map = MEM_mallocN(sizeof(int) * totface, __func__);
int i, j;
for (i = 0, j = 0; j < totface; i++, j++) {
face_as_quad_map[i] = j;
/* step over all quads */
if (mpoly[looptri[j].poly].totloop == 4) {
j++; /* skips the nest looptri */
}
}
num_face_as_quad_map = i;
}
else {
num_face_as_quad_map = totface;
}
#endif
/* new computation method */
{
SGLSLMeshToTangent mesh2tangent = {NULL};
@ -3150,6 +3299,11 @@ void DM_calc_loop_tangents(DerivedMesh *dm)
mesh2tangent.tangent = tangent;
mesh2tangent.numTessFaces = totface;
#ifdef USE_LOOPTRI_DETECT_QUADS
mesh2tangent.face_as_quad_map = face_as_quad_map;
mesh2tangent.num_face_as_quad_map = num_face_as_quad_map;
#endif
sContext.m_pUserData = &mesh2tangent;
sContext.m_pInterface = &sInterface;
sInterface.m_getNumFaces = dm_ts_GetNumFaces;
@ -3161,6 +3315,13 @@ void DM_calc_loop_tangents(DerivedMesh *dm)
/* 0 if failed */
genTangSpaceDefault(&sContext);
#ifdef USE_LOOPTRI_DETECT_QUADS
if (face_as_quad_map) {
MEM_freeN(face_as_quad_map);
}
#undef USE_LOOPTRI_DETECT_QUADS
#endif
}
}

View File

@ -240,6 +240,9 @@ static void emDM_calcLoopNormalsSpaceArray(
/** \name Tangent Space Calculation
* \{ */
/* Necessary complexity to handle looptri's as quads for correct tangents */
#define USE_LOOPTRI_DETECT_QUADS
typedef struct {
const float (*precomputedFaceNormals)[3];
const float (*precomputedLoopNormals)[3];
@ -249,22 +252,56 @@ typedef struct {
float (*tangent)[4]; /* destination */
int numTessFaces;
#ifdef USE_LOOPTRI_DETECT_QUADS
/* map from 'fake' face index to looptri,
* quads will point to the first looptri of the quad */
const int *face_as_quad_map;
int num_face_as_quad_map;
#endif
} SGLSLEditMeshToTangent;
#ifdef USE_LOOPTRI_DETECT_QUADS
/* seems weak but only used on quads */
static const BMLoop *bm_loop_at_face_index(const BMFace *f, int vert_index)
{
const BMLoop *l = BM_FACE_FIRST_LOOP(f);
while (vert_index--) {
l = l->next;
}
return l;
}
#endif
/* interface */
#include "mikktspace.h"
static int emdm_ts_GetNumFaces(const SMikkTSpaceContext *pContext)
{
SGLSLEditMeshToTangent *pMesh = pContext->m_pUserData;
#ifdef USE_LOOPTRI_DETECT_QUADS
return pMesh->num_face_as_quad_map;
#else
return pMesh->numTessFaces;
#endif
}
static int emdm_ts_GetNumVertsOfFace(const SMikkTSpaceContext *pContext, const int face_num)
{
//SGLSLEditMeshToTangent *pMesh = pContext->m_pUserData;
#ifdef USE_LOOPTRI_DETECT_QUADS
SGLSLEditMeshToTangent *pMesh = pContext->m_pUserData;
if (pMesh->face_as_quad_map) {
const BMLoop **lt = pMesh->looptris[pMesh->face_as_quad_map[face_num]];
if (lt[0]->f->len == 4) {
return 4;
}
}
return 3;
#else
UNUSED_VARS(pContext, face_num);
return 3;
#endif
}
static void emdm_ts_GetPosition(
@ -273,8 +310,30 @@ static void emdm_ts_GetPosition(
{
//assert(vert_index >= 0 && vert_index < 4);
SGLSLEditMeshToTangent *pMesh = pContext->m_pUserData;
const BMLoop **lt = pMesh->looptris[face_num];
const float *co = lt[vert_index]->v->co;
const BMLoop **lt;
const BMLoop *l;
#ifdef USE_LOOPTRI_DETECT_QUADS
if (pMesh->face_as_quad_map) {
lt = pMesh->looptris[pMesh->face_as_quad_map[face_num]];
if (lt[0]->f->len == 4) {
l = bm_loop_at_face_index(lt[0]->f, vert_index);
goto finally;
}
/* fall through to regular triangle */
}
else {
lt = pMesh->looptris[face_num];
}
#else
lt = pMesh->looptris[face_num];
#endif
l = lt[vert_index];
const float *co;
finally:
co = l->v->co;
copy_v3_v3(r_co, co);
}
@ -284,14 +343,33 @@ static void emdm_ts_GetTextureCoordinate(
{
//assert(vert_index >= 0 && vert_index < 4);
SGLSLEditMeshToTangent *pMesh = pContext->m_pUserData;
const BMLoop **lt = pMesh->looptris[face_num];
const BMLoop **lt;
const BMLoop *l;
#ifdef USE_LOOPTRI_DETECT_QUADS
if (pMesh->face_as_quad_map) {
lt = pMesh->looptris[pMesh->face_as_quad_map[face_num]];
if (lt[0]->f->len == 4) {
l = bm_loop_at_face_index(lt[0]->f, vert_index);
goto finally;
}
/* fall through to regular triangle */
}
else {
lt = pMesh->looptris[face_num];
}
#else
lt = pMesh->looptris[face_num];
#endif
l = lt[vert_index];
finally:
if (pMesh->cd_loop_uv_offset != -1) {
const float *uv = BM_ELEM_CD_GET_VOID_P(lt[vert_index], pMesh->cd_loop_uv_offset);
const float *uv = BM_ELEM_CD_GET_VOID_P(l, pMesh->cd_loop_uv_offset);
copy_v2_v2(r_uv, uv);
}
else {
const float *orco = pMesh->orco[BM_elem_index_get(lt[vert_index]->v)];
const float *orco = pMesh->orco[BM_elem_index_get(l->v)];
map_to_sphere(&r_uv[0], &r_uv[1], orco[0], orco[1], orco[2]);
}
}
@ -302,22 +380,40 @@ static void emdm_ts_GetNormal(
{
//assert(vert_index >= 0 && vert_index < 4);
SGLSLEditMeshToTangent *pMesh = pContext->m_pUserData;
const BMLoop **lt = pMesh->looptris[face_num];
const bool smoothnormal = BM_elem_flag_test_bool(lt[0]->f, BM_ELEM_SMOOTH);
const BMLoop **lt;
const BMLoop *l;
if (pMesh->precomputedLoopNormals) {
copy_v3_v3(r_no, pMesh->precomputedLoopNormals[BM_elem_index_get(lt[vert_index])]);
#ifdef USE_LOOPTRI_DETECT_QUADS
if (pMesh->face_as_quad_map) {
lt = pMesh->looptris[pMesh->face_as_quad_map[face_num]];
if (lt[0]->f->len == 4) {
l = bm_loop_at_face_index(lt[0]->f, vert_index);
goto finally;
}
/* fall through to regular triangle */
}
else if (!smoothnormal) {
else {
lt = pMesh->looptris[face_num];
}
#else
lt = pMesh->looptris[face_num];
#endif
l = lt[vert_index];
finally:
if (pMesh->precomputedLoopNormals) {
copy_v3_v3(r_no, pMesh->precomputedLoopNormals[BM_elem_index_get(l)]);
}
else if (BM_elem_flag_test(l->f, BM_ELEM_SMOOTH) == 0) { /* flat */
if (pMesh->precomputedFaceNormals) {
copy_v3_v3(r_no, pMesh->precomputedFaceNormals[BM_elem_index_get(lt[0]->f)]);
copy_v3_v3(r_no, pMesh->precomputedFaceNormals[BM_elem_index_get(l->f)]);
}
else {
copy_v3_v3(r_no, lt[0]->f->no);
copy_v3_v3(r_no, l->f->no);
}
}
else {
copy_v3_v3(r_no, lt[vert_index]->v->no);
copy_v3_v3(r_no, l->v->no);
}
}
@ -327,8 +423,30 @@ static void emdm_ts_SetTSpace(
{
//assert(vert_index >= 0 && vert_index < 4);
SGLSLEditMeshToTangent *pMesh = pContext->m_pUserData;
const BMLoop **lt = pMesh->looptris[face_num];
float *pRes = pMesh->tangent[BM_elem_index_get(lt[vert_index])];
const BMLoop **lt;
const BMLoop *l;
#ifdef USE_LOOPTRI_DETECT_QUADS
if (pMesh->face_as_quad_map) {
lt = pMesh->looptris[pMesh->face_as_quad_map[face_num]];
if (lt[0]->f->len == 4) {
l = bm_loop_at_face_index(lt[0]->f, vert_index);
goto finally;
}
/* fall through to regular triangle */
}
else {
lt = pMesh->looptris[face_num];
}
#else
lt = pMesh->looptris[face_num];
#endif
l = lt[vert_index];
float *pRes;
finally:
pRes = pMesh->tangent[BM_elem_index_get(l)];
copy_v3_v3(pRes, fvTangent);
pRes[3] = fSign;
}
@ -389,6 +507,31 @@ static void emDM_calcLoopTangents(DerivedMesh *dm)
DM_add_loop_layer(dm, CD_TANGENT, CD_CALLOC, NULL);
tangent = DM_get_loop_data_layer(dm, CD_TANGENT);
#ifdef USE_LOOPTRI_DETECT_QUADS
int num_face_as_quad_map;
int *face_as_quad_map = NULL;
/* map faces to quads */
if (bmdm->em->tottri != bm->totface) {
/* over alloc, since we dont know how many ngon or quads we have */
/* map fake face index to looptri */
face_as_quad_map = MEM_mallocN(sizeof(int) * totface, __func__);
int i, j;
for (i = 0, j = 0; j < totface; i++, j++) {
face_as_quad_map[i] = j;
/* step over all quads */
if (em->looptris[j][0]->f->len == 4) {
j++; /* skips the nest looptri */
}
}
num_face_as_quad_map = i;
}
else {
num_face_as_quad_map = totface;
}
#endif
/* new computation method */
{
SGLSLEditMeshToTangent mesh2tangent = {NULL};
@ -403,6 +546,11 @@ static void emDM_calcLoopTangents(DerivedMesh *dm)
mesh2tangent.tangent = tangent;
mesh2tangent.numTessFaces = totface;
#ifdef USE_LOOPTRI_DETECT_QUADS
mesh2tangent.face_as_quad_map = face_as_quad_map;
mesh2tangent.num_face_as_quad_map = num_face_as_quad_map;
#endif
sContext.m_pUserData = &mesh2tangent;
sContext.m_pInterface = &sInterface;
sInterface.m_getNumFaces = emdm_ts_GetNumFaces;
@ -414,6 +562,13 @@ static void emDM_calcLoopTangents(DerivedMesh *dm)
/* 0 if failed */
genTangSpaceDefault(&sContext);
#ifdef USE_LOOPTRI_DETECT_QUADS
if (face_as_quad_map) {
MEM_freeN(face_as_quad_map);
}
#undef USE_LOOPTRI_DETECT_QUADS
#endif
}
}