Finish 3D dynamic level set

include/taichi/math/dynamic_levelset_3d.cpp

@@ -0,0 +1,50 @@
+/*******************************************************************************
+    Taichi - Physically based Computer Graphics Library
+
+    Copyright (c) 2017 Yu Fang <squarefk@gmail.com>
+
+    All rights reserved. Use of this source code is governed by
+    the MIT license as written in the LICENSE file.
+*******************************************************************************/
+
+#include "dynamic_levelset_3d.h"
+
+TC_NAMESPACE_BEGIN
+
+void DynamicLevelSet3D::initialize(real _t0, real _t1, const LevelSet3D &_ls0, const LevelSet3D &_ls1) {
+    t0 = _t0;
+    t1 = _t1;
+    levelset0 = std::make_shared<LevelSet3D>(_ls0);
+    levelset1 = std::make_shared<LevelSet3D>(_ls1);
+}
+
+Vector3 DynamicLevelSet3D::get_spatial_gradient(const Vector3 &pos, real t) {
+    Vector3 gxyz0 = levelset0->get_gradient(pos);
+    Vector3 gxyz1 = levelset1->get_gradient(pos);
+    real gx = lerp((t - t0) / (t1 - t0), gxyz0.x, gxyz1.x);
+    real gy = lerp((t - t0) / (t1 - t0), gxyz0.y, gxyz1.y);
+    real gz = lerp((t - t0) / (t1 - t0), gxyz0.z, gxyz1.z);
+    return Vector3(gx, gy, gz);
+}
+
+real DynamicLevelSet3D::get_temporal_gradient(const Vector3 &pos, real t) {
+    real l1 = levelset0->get(pos);
+    real l2 = levelset1->get(pos);
+    return (l2 - l1) / (t1 - t0);
+}
+
+Array3D<real> DynamicLevelSet3D::rasterize(int width, int height, int depth, real t) {
+    Array3D<real> r0 = levelset0->rasterize(width, height, depth);
+    Array3D<real> r1 = levelset1->rasterize(width, height, depth);
+    Array3D<real> out(width, height, width);
+    for (auto &ind : Region3D(0, width, 0, height, 0, depth, Vector3(0.5f, 0.5f, 0.5f))) {
+        out[ind] = lerp((t - t0) / (t1 - t0), r0[ind], r1[ind]);
+        if (std::isnan(out[ind])) {
+            out[ind] = std::numeric_limits<real>::infinity();
+        }
+    }
+    return out;
+}
+
+
+TC_NAMESPACE_END

include/taichi/math/dynamic_levelset_3d.h

@@ -0,0 +1,35 @@
+/*******************************************************************************
+    Taichi - Physically based Computer Graphics Library
+
+    Copyright (c) 2017 Yu Fang <squarefk@gmail.com>
+
+    All rights reserved. Use of this source code is governed by
+    the MIT license as written in the LICENSE file.
+*******************************************************************************/
+
+#pragma once
+
+
+#include <limits>
+#include <memory>
+#include <taichi/math/levelset_3d.h>
+
+
+TC_NAMESPACE_BEGIN
+
+class DynamicLevelSet3D {
+public:
+    real t0, t1;
+    std::shared_ptr<LevelSet3D> levelset0, levelset1;
+
+    void initialize(real _t0, real _t1, const LevelSet3D &_ls0, const LevelSet3D &_ls1);
+
+    Vector3 get_spatial_gradient(const Vector3 &pos, real t);
+
+    real get_temporal_gradient(const Vector3 &pos, real t);
+
+    Array3D<real> rasterize(int width, int height, int depth, real t);
+};
+
+TC_NAMESPACE_END
+