[Bf-blender-cvs] [0fec2a9] alembic_basic_io: Curves: rewrite the code a bit so it works with external files.
Kévin Dietrich
noreply at git.blender.org
Wed Jul 6 01:36:52 CEST 2016
Commit: 0fec2a923b58bc4b144a31c2959a24d4d3d338dd
Author: Kévin Dietrich
Date: Wed Jul 6 00:21:23 2016 +0200
Branches: alembic_basic_io
https://developer.blender.org/rB0fec2a923b58bc4b144a31c2959a24d4d3d338dd
Curves: rewrite the code a bit so it works with external files.
- Pad start and end of knots array with dummy knots.
- Duplicate control points in case of a cyclic curve.
There are still a couple of issues (fringe cases) though which should be
documented in the comments.
===================================================================
M source/blender/alembic/intern/abc_curves.cc
===================================================================
diff --git a/source/blender/alembic/intern/abc_curves.cc b/source/blender/alembic/intern/abc_curves.cc
index bf8c04d..15442fb 100644
--- a/source/blender/alembic/intern/abc_curves.cc
+++ b/source/blender/alembic/intern/abc_curves.cc
@@ -92,19 +92,11 @@ void AbcCurveWriter::do_write()
Nurb *nurbs = static_cast<Nurb *>(curve->nurb.first);
for (; nurbs; nurbs = nurbs->next) {
- if ((nurbs->flagu & CU_NURB_ENDPOINT) != 0) {
- periodicity = Alembic::AbcGeom::kNonPeriodic;
- }
- else if ((nurbs->flagu & CU_NURB_CYCLIC) != 0) {
- periodicity = Alembic::AbcGeom::kPeriodic;
- }
-
if (nurbs->bp) {
curve_basis = Alembic::AbcGeom::kNoBasis;
curve_type = Alembic::AbcGeom::kLinear;
const int totpoint = nurbs->pntsu * nurbs->pntsv;
- vert_counts.push_back(totpoint);
const BPoint *point = nurbs->bp;
@@ -120,7 +112,6 @@ void AbcCurveWriter::do_write()
curve_type = Alembic::AbcGeom::kCubic;
const int totpoint = nurbs->pntsu;
- vert_counts.push_back(totpoint);
const BezTriple *bezier = nurbs->bezt;
@@ -132,11 +123,42 @@ void AbcCurveWriter::do_write()
}
}
- for (int i = 0; i < KNOTSU(nurbs); ++i) {
- knots.push_back(nurbs->knotsu[i]);
+ if ((nurbs->flagu & CU_NURB_ENDPOINT) != 0) {
+ periodicity = Alembic::AbcGeom::kNonPeriodic;
+ }
+ else if ((nurbs->flagu & CU_NURB_CYCLIC) != 0) {
+ periodicity = Alembic::AbcGeom::kPeriodic;
+
+ /* Duplicate the start points to indicate that the curve is actually
+ * cyclic since other software need those.
+ */
+
+ for (int i = 0; i < nurbs->orderu; ++i) {
+ verts.push_back(verts[i]);
+ }
+ }
+
+ const size_t num_knots = KNOTSU(nurbs);
+
+ /* Add an extra knot at the beggining and end of the array since most apps
+ * require/expect them. */
+ knots.resize(num_knots + 2);
+
+ for (int i = 0; i < num_knots; ++i) {
+ knots[i + 1] = nurbs->knotsu[i];
}
- orders.push_back(nurbs->orderu);
+ if ((nurbs->flagu & CU_NURB_CYCLIC) != 0) {
+ knots[0] = nurbs->knotsu[0];
+ knots[num_knots - 1] = nurbs->knotsu[num_knots - 1];
+ }
+ else {
+ knots[0] = (2.0f * nurbs->knotsu[0] - nurbs->knotsu[1]);
+ knots[num_knots - 1] = (2.0f * nurbs->knotsu[num_knots - 1] - nurbs->knotsu[num_knots - 2]);
+ }
+
+ orders.push_back(nurbs->orderu + 1);
+ vert_counts.push_back(verts.size());
}
Alembic::AbcGeom::OFloatGeomParam::Sample width_sample;
@@ -206,40 +228,84 @@ void AbcCurveReader::readObjectData(Main *bmain, Scene *scene, float time)
size_t idx = 0;
for (size_t i = 0; i < num_vertices->size(); ++i) {
- const int steps = (*num_vertices)[i];
+ const int num_verts = (*num_vertices)[i];
Nurb *nu = static_cast<Nurb *>(MEM_callocN(sizeof(Nurb), "abc_getnurb"));
- nu->bp = static_cast<BPoint *>(MEM_callocN(sizeof(BPoint) * steps, "abc_getnurb"));
- nu->type = CU_NURBS;
nu->resolu = cu->resolu;
nu->resolv = cu->resolv;
- nu->pntsu = steps;
+ nu->pntsu = num_verts;
nu->pntsv = 1;
nu->flag |= CU_SMOOTH;
+ nu->orderu = 1;
+
+ if (smp.getType() == Alembic::AbcGeom::kCubic) {
+ nu->orderu = 3;
+ }
+ else if (orders->size() > i) {
+ nu->orderu = static_cast<short>((*orders)[i] - 1);
+ }
+
if (periodicity == Alembic::AbcGeom::kNonPeriodic) {
nu->flagu |= CU_NURB_ENDPOINT;
}
else if (periodicity == Alembic::AbcGeom::kPeriodic) {
nu->flagu |= CU_NURB_CYCLIC;
+
+ /* Check the number of points which overlap, we don't have
+ * overlapping points in Blender, but other software do use them to
+ * indicate that a curve is actually cyclic. Usually the number of
+ * overlapping points is equal to the order/degree of the curve.
+ */
+
+ const int start = idx;
+ const int end = idx + num_verts;
+ int overlap = 0;
+
+ for (int j = start, k = end - nu->orderu; j < nu->orderu; ++j, ++k) {
+ const Imath::V3f &p1 = (*positions)[j];
+ const Imath::V3f &p2 = (*positions)[k];
+
+ if (p1 != p2) {
+ break;
+ }
+
+ ++overlap;
+ }
+
+ /* TODO: Special case, need to figure out how it coincides with knots. */
+ if (overlap == 0 && num_verts > 2 && (*positions)[start] == (*positions)[end - 1]) {
+ overlap = 1;
+ }
+
+ /* There is no real cycles. */
+ if (overlap == 0) {
+ nu->flagu &= ~CU_NURB_CYCLIC;
+ nu->flagu |= CU_NURB_ENDPOINT;
+ }
+
+ nu->pntsu -= overlap;
}
- nu->orderu = (orders) ? (*orders)[i]
- : (periodicity == Alembic::AbcGeom::kPeriodic) ? 4 : steps;
+ float weight = 1.0f;
+
+ const bool do_radius = (radiuses != NULL) && (radiuses->size() > 1);
+ float radius = (radiuses->size() == 1) ? (*radiuses)[0] : 1.0f;
+ nu->type = CU_NURBS;
+
+ nu->bp = static_cast<BPoint *>(MEM_callocN(sizeof(BPoint) * nu->pntsu, "abc_getnurb"));
BPoint *bp = nu->bp;
- float radius = 1.0f;
- float weight = 1.0f;
- for (int j = 0; j < steps; ++j, ++bp) {
- const Imath::V3f &pos = (*positions)[idx++];
+ for (int j = 0; j < nu->pntsu; ++j, ++bp, ++idx) {
+ const Imath::V3f &pos = (*positions)[idx];
- if (radiuses) {
- radius = (*radiuses)[i];
+ if (do_radius) {
+ radius = (*radiuses)[idx];
}
if (weights) {
- weight = (*weights)[i];
+ weight = (*weights)[idx];
}
copy_yup_zup(bp->vec, pos.getValue());
@@ -252,11 +318,20 @@ void AbcCurveReader::readObjectData(Main *bmain, Scene *scene, float time)
if (knots && knots->size() != 0) {
nu->knotsu = static_cast<float *>(MEM_callocN(KNOTSU(nu) * sizeof(float), "abc_setsplineknotsu"));
- for (size_t i = 0; i < KNOTSU(nu); ++i) {
- nu->knotsu[i] = (*knots)[knot_offset + i];
+ /* TODO: second check is temporary, for until the check for cycles is rock solid. */
+ if (periodicity == Alembic::AbcGeom::kPeriodic && (KNOTSU(nu) == knots->size() - 2)) {
+ /* Skip first and last knots. */
+ for (size_t i = 1; i < knots->size() - 1; ++i) {
+ nu->knotsu[i - 1] = (*knots)[knot_offset + i];
+ }
+ }
+ else {
+ /* TODO: figure out how to use the knots array from other
+ * software in this case. */
+ BKE_nurb_knot_calc_u(nu);
}
- knot_offset += KNOTSU(nu);
+ knot_offset += knots->size();
}
else {
BKE_nurb_knot_calc_u(nu);
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