[Bf-blender-cvs] SVN commit: /data/svn/bf-blender [14113] trunk/blender/source/blender: added mesh.getTangents() to the python api
Campbell Barton
ideasman42 at gmail.com
Fri Mar 14 19:54:03 CET 2008
Revision: 14113
http://projects.blender.org/plugins/scmsvn/viewcvs.php?view=rev&root=bf-blender&revision=14113
Author: campbellbarton
Date: 2008-03-14 19:53:51 +0100 (Fri, 14 Mar 2008)
Log Message:
-----------
added mesh.getTangents() to the python api
Modified Paths:
--------------
trunk/blender/source/blender/blenlib/BLI_arithb.h
trunk/blender/source/blender/blenlib/intern/arithb.c
trunk/blender/source/blender/python/api2_2x/Mesh.c
trunk/blender/source/blender/python/api2_2x/doc/Mesh.py
trunk/blender/source/blender/render/intern/source/convertblender.c
Modified: trunk/blender/source/blender/blenlib/BLI_arithb.h
===================================================================
--- trunk/blender/source/blender/blenlib/BLI_arithb.h 2008-03-14 18:21:06 UTC (rev 14112)
+++ trunk/blender/source/blender/blenlib/BLI_arithb.h 2008-03-14 18:53:51 UTC (rev 14113)
@@ -400,6 +400,16 @@
void DQuatMulVecfl(DualQuat *dq, float *co, float mat[][3]);
void DQuatCpyDQuat(DualQuat *dq1, DualQuat *dq2);
+/* Tangent stuff */
+typedef struct VertexTangent {
+ float tang[3], uv[2];
+ struct VertexTangent *next;
+} VertexTangent;
+
+void sum_or_add_vertex_tangent(void *arena, VertexTangent **vtang, float *tang, float *uv);
+float *find_vertex_tangent(VertexTangent *vtang, float *uv);
+void tangent_from_uv(float *uv1, float *uv2, float *uv3, float *co1, float *co2, float *co3, float *n, float *tang);
+
#ifdef __cplusplus
}
#endif
Modified: trunk/blender/source/blender/blenlib/intern/arithb.c
===================================================================
--- trunk/blender/source/blender/blenlib/intern/arithb.c 2008-03-14 18:21:06 UTC (rev 14112)
+++ trunk/blender/source/blender/blenlib/intern/arithb.c 2008-03-14 18:53:51 UTC (rev 14113)
@@ -57,6 +57,7 @@
#include <stdio.h>
#include "BLI_arithb.h"
+#include "BLI_memarena.h"
/* A few small defines. Keep'em local! */
#define SMALL_NUMBER 1.e-8
@@ -4268,3 +4269,75 @@
mat[3][1] = loc[1];
mat[3][2] = loc[2];
}
+
+/* Tangents */
+
+/* For normal map tangents we need to detect uv boundaries, and only average
+ * tangents in case the uvs are connected. Alternative would be to store 1
+ * tangent per face rather than 4 per face vertex, but that's not compatible
+ * with games */
+
+
+/* from BKE_mesh.h */
+#define STD_UV_CONNECT_LIMIT 0.0001f
+
+void sum_or_add_vertex_tangent(void *arena, VertexTangent **vtang, float *tang, float *uv)
+{
+ VertexTangent *vt;
+
+ /* find a tangent with connected uvs */
+ for(vt= *vtang; vt; vt=vt->next) {
+ if(fabs(uv[0]-vt->uv[0]) < STD_UV_CONNECT_LIMIT && fabs(uv[1]-vt->uv[1]) < STD_UV_CONNECT_LIMIT) {
+ VecAddf(vt->tang, vt->tang, tang);
+ return;
+ }
+ }
+
+ /* if not found, append a new one */
+ vt= BLI_memarena_alloc((MemArena *)arena, sizeof(VertexTangent));
+ VecCopyf(vt->tang, tang);
+ vt->uv[0]= uv[0];
+ vt->uv[1]= uv[1];
+
+ if(*vtang)
+ vt->next= *vtang;
+ *vtang= vt;
+}
+
+float *find_vertex_tangent(VertexTangent *vtang, float *uv)
+{
+ VertexTangent *vt;
+ static float nulltang[3] = {0.0f, 0.0f, 0.0f};
+
+ for(vt= vtang; vt; vt=vt->next)
+ if(fabs(uv[0]-vt->uv[0]) < STD_UV_CONNECT_LIMIT && fabs(uv[1]-vt->uv[1]) < STD_UV_CONNECT_LIMIT)
+ return vt->tang;
+
+ return nulltang; /* shouldn't happen, except for nan or so */
+}
+
+void tangent_from_uv(float *uv1, float *uv2, float *uv3, float *co1, float *co2, float *co3, float *n, float *tang)
+{
+ float tangv[3], ct[3], e1[3], e2[3], s1, t1, s2, t2, det;
+
+ s1= uv2[0] - uv1[0];
+ s2= uv3[0] - uv1[0];
+ t1= uv2[1] - uv1[1];
+ t2= uv3[1] - uv1[1];
+ det= 1.0f / (s1 * t2 - s2 * t1);
+
+ /* normals in render are inversed... */
+ VecSubf(e1, co1, co2);
+ VecSubf(e2, co1, co3);
+ tang[0] = (t2*e1[0] - t1*e2[0])*det;
+ tang[1] = (t2*e1[1] - t1*e2[1])*det;
+ tang[2] = (t2*e1[2] - t1*e2[2])*det;
+ tangv[0] = (s1*e2[0] - s2*e1[0])*det;
+ tangv[1] = (s1*e2[1] - s2*e1[1])*det;
+ tangv[2] = (s1*e2[2] - s2*e1[2])*det;
+ Crossf(ct, tang, tangv);
+
+ /* check flip */
+ if ((ct[0]*n[0] + ct[1]*n[1] + ct[2]*n[2]) < 0.0f)
+ VecMulf(tang, -1.0f);
+}
Modified: trunk/blender/source/blender/python/api2_2x/Mesh.c
===================================================================
--- trunk/blender/source/blender/python/api2_2x/Mesh.c 2008-03-14 18:21:06 UTC (rev 14112)
+++ trunk/blender/source/blender/python/api2_2x/Mesh.c 2008-03-14 18:53:51 UTC (rev 14113)
@@ -75,6 +75,7 @@
#include "BLI_arithb.h"
#include "BLI_blenlib.h"
+#include "BLI_memarena.h"
#include "blendef.h"
#include "mydevice.h"
@@ -7494,6 +7495,177 @@
}
+/* This is a bit nasty, Blenders tangents are computed for rendering, and this isnt compatible with a normal Mesh
+ * so we have to rewrite parts of it here, make sure these stay in sync */
+
+static PyObject *Mesh_getTangents( BPy_Mesh * self )
+{
+ /* python stuff */
+ PyObject *py_tanlist;
+ PyObject *py_tuple;
+
+
+ PyObject *py_vector;
+#if 0 /* BI-TANGENT */
+ PyObject *py_bivector;
+ PyObject *py_pair;
+
+ float no[3];
+#endif
+ /* mesh vars */
+ Mesh *mesh = self->mesh;
+ MTFace *tf = mesh->mtface;
+ MFace *mf = mesh->mface;
+ MVert *v1, *v2, *v3, *v4;
+ int mf_vi[4];
+
+ /* See convertblender.c */
+ float *uv1, *uv2, *uv3, *uv4;
+ float fno[3];
+ float tang[3];
+ float uv[4][2];
+ float *vtang;
+
+ float (*orco)[3] = NULL;
+
+ MemArena *arena= NULL;
+ VertexTangent **vtangents= NULL;
+ int i, j, len;
+
+
+ if(!mesh->mtface) {
+ if (!self->object)
+ return EXPP_ReturnPyObjError( PyExc_RuntimeError, "cannot get tangents when there are not UV's, or the mesh has no link to an object");
+
+ orco = (float(*)[3])get_mesh_orco_verts(self->object);
+
+ if (!orco)
+ return EXPP_ReturnPyObjError( PyExc_RuntimeError, "cannot get orco's for this objects tangents");
+ }
+
+ /* vertex normals */
+ arena= BLI_memarena_new(BLI_MEMARENA_STD_BUFSIZE);
+ BLI_memarena_use_calloc(arena);
+ vtangents= MEM_callocN(sizeof(VertexTangent*)*mesh->totvert, "VertexTangent");
+
+ for( i = 0, tf = mesh->mtface, mf = mesh->mface; i < mesh->totface; mf++, tf++, i++ ) {
+ v1 = &mesh->mvert[mf->v1];
+ v2 = &mesh->mvert[mf->v2];
+ v3 = &mesh->mvert[mf->v3];
+ if (mf->v4) {
+ v4 = &mesh->mvert[mf->v4];
+
+ CalcNormFloat4( v1->co, v2->co, v3->co, v4->co, fno );
+ } else {
+ CalcNormFloat( v1->co, v2->co, v3->co, fno );
+ }
+
+ if(mesh->mtface) {
+ uv1= tf->uv[0];
+ uv2= tf->uv[1];
+ uv3= tf->uv[2];
+ uv4= tf->uv[3];
+ } else {
+ uv1= uv[0]; uv2= uv[1]; uv3= uv[2]; uv4= uv[3];
+ spheremap(orco[mf->v1][0], orco[mf->v1][1], orco[mf->v1][2], &uv[0][0], &uv[0][1]);
+ spheremap(orco[mf->v2][0], orco[mf->v2][1], orco[mf->v2][2], &uv[1][0], &uv[1][1]);
+ spheremap(orco[mf->v3][0], orco[mf->v3][1], orco[mf->v3][2], &uv[2][0], &uv[2][1]);
+ if(v4)
+ spheremap(orco[mf->v4][0], orco[mf->v4][1], orco[mf->v4][2], &uv[3][0], &uv[3][1]);
+ }
+
+ tangent_from_uv(uv1, uv2, uv3, v1->co, v2->co, v3->co, fno, tang);
+ sum_or_add_vertex_tangent(arena, &vtangents[mf->v1], tang, uv1);
+ sum_or_add_vertex_tangent(arena, &vtangents[mf->v2], tang, uv2);
+ sum_or_add_vertex_tangent(arena, &vtangents[mf->v3], tang, uv3);
+
+ if (mf->v4) {
+ v4 = &mesh->mvert[mf->v4];
+
+ tangent_from_uv(uv1, uv3, uv4, v1->co, v3->co, v4->co, fno, tang);
+ sum_or_add_vertex_tangent(arena, &vtangents[mf->v1], tang, uv1);
+ sum_or_add_vertex_tangent(arena, &vtangents[mf->v3], tang, uv3);
+ sum_or_add_vertex_tangent(arena, &vtangents[mf->v4], tang, uv4);
+ }
+ }
+
+
+ py_tanlist = PyList_New(mesh->totface);
+
+ for( i = 0, tf = mesh->mtface, mf = mesh->mface; i < mesh->totface; mf++, tf++, i++ ) {
+
+ len = mf->v4 ? 4 : 3;
+
+ if(mesh->mtface) {
+ uv1= tf->uv[0];
+ uv2= tf->uv[1];
+ uv3= tf->uv[2];
+ uv4= tf->uv[3];
+ } else {
+ uv1= uv[0]; uv2= uv[1]; uv3= uv[2]; uv4= uv[3];
+ spheremap(orco[mf->v1][0], orco[mf->v1][1], orco[mf->v1][2], &uv[0][0], &uv[0][1]);
+ spheremap(orco[mf->v2][0], orco[mf->v2][1], orco[mf->v2][2], &uv[1][0], &uv[1][1]);
+ spheremap(orco[mf->v3][0], orco[mf->v3][1], orco[mf->v3][2], &uv[2][0], &uv[2][1]);
+ if(len==4)
+ spheremap(orco[mf->v4][0], orco[mf->v4][1], orco[mf->v4][2], &uv[3][0], &uv[3][1]);
+ }
+
+ mf_vi[0] = mf->v1;
+ mf_vi[1] = mf->v2;
+ mf_vi[2] = mf->v3;
+ mf_vi[3] = mf->v4;
+
+#if 0 /* BI-TANGENT */
+ /* now calculate the bitangent */
+ if (mf->flag & ME_SMOOTH) {
+ no[0] = (float)(mesh->mvert[mf_vi[j]]->no[0] / 32767.0);
+ no[1] = (float)(mesh->mvert[mf_vi[j]]->no[1] / 32767.0);
+ no[2] = (float)(mesh->mvert[mf_vi[j]]->no[2] / 32767.0);
+ } else {
+ /* calc face normal */
+ if (len==4) CalcNormFloat4( mesh->mvert[0]->co, mesh->mvert[1]->co, mesh->mvert[2]->co, mesh->mvert[3]->co, no );
+ else CalcNormFloat4( mesh->mvert[0]->co, mesh->mvert[1]->co, mesh->mvert[2]->co, no );
+ }
+#endif
+
+ py_tuple = PyTuple_New( len );
+
+ for (j=0; j<len; j++) {
+ vtang= find_vertex_tangent(vtangents[mf_vi[j]], mesh->mtface ? tf->uv[j] : uv[j]); /* mf_vi[j] == mf->v1, uv[j] == tf->uv[0] */
+
+ py_vector = newVectorObject( vtang, 3, Py_NEW );
+ Normalize(((VectorObject *)py_vector)->vec);
+
+#if 0 /* BI-TANGENT */
+ py_pair = PyTuple_New( 2 );
+ PyTuple_SetItem( py_pair, 0, py_vector );
+ PyTuple_SetItem( py_pair, 1, py_bivector );
+
+ /* qdn: tangent space */
+ /* copied from texture.c */
+ float B[3], tv[3];
+ Crossf(B, shi->vn, shi->nmaptang); /* bitangent */
+ /* transform norvec from tangent space to object surface in camera space */
+ tv[0] = texres.nor[0]*shi->nmaptang[0] + texres.nor[1]*B[0] + texres.nor[2]*shi->vn[0];
+ tv[1] = texres.nor[0]*shi->nmaptang[1] + texres.nor[1]*B[1] + texres.nor[2]*shi->vn[1];
+ tv[2] = texres.nor[0]*shi->nmaptang[2] + texres.nor[1]*B[2] + texres.nor[2]*shi->vn[2];
+ shi->vn[0]= facm*shi->vn[0] + fact*tv[0];
+ shi->vn[1]= facm*shi->vn[1] + fact*tv[1];
+ shi->vn[2]= facm*shi->vn[2] + fact*tv[2];
+ PyTuple_SetItem( py_tuple, j, py_pair );
+#else
+ PyTuple_SetItem( py_tuple, j, py_vector );
+#endif
+ }
+
+ PyList_SetItem( py_tanlist, i, py_tuple );
+ }
+ if (orco)
+ MEM_freeN( orco );
+
+ return py_tanlist;
+}
+
/*
* "__copy__" return a copy of the mesh
*/
@@ -7571,7 +7743,9 @@
"Recalculates inside or outside normals (experimental)"},
{"pointInside", (PyCFunction)Mesh_pointInside, METH_VARARGS|METH_KEYWORDS,
"Recalculates inside or outside normals (experimental)"},
-
+ {"getTangents", (PyCFunction)Mesh_getTangents, METH_VARARGS|METH_KEYWORDS,
+ "Return a list of face tangents"},
+
/* mesh custom data layers */
{"addUVLayer", (PyCFunction)Mesh_addUVLayer, METH_VARARGS,
"adds a UV layer to this mesh"},
Modified: trunk/blender/source/blender/python/api2_2x/doc/Mesh.py
===================================================================
--- trunk/blender/source/blender/python/api2_2x/doc/Mesh.py 2008-03-14 18:21:06 UTC (rev 14112)
+++ trunk/blender/source/blender/python/api2_2x/doc/Mesh.py 2008-03-14 18:53:51 UTC (rev 14113)
@@ -844,7 +844,45 @@
@note: Only returns a valid result for mesh data that has no holes.
@@ Diff output truncated at 10240 characters. @@
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