[Bf-blender-cvs] [26d0bbffa89] functions: added point force node for particle nodes

[Martin Felke]

Commit: 26d0bbffa89e364ca430407a0f59b16a15cf2785
Author: Martin Felke
Date:   Tue Jul 30 14:39:25 2019 +0200
Branches: functions
https://developer.blender.org/rB26d0bbffa89e364ca430407a0f59b16a15cf2785

added point force node for particle nodes

===================================================================

A	release/scripts/startup/nodes/bparticle_nodes/point_force.py
M	source/blender/simulations/bparticles/forces.cpp
M	source/blender/simulations/bparticles/forces.hpp
M	source/blender/simulations/bparticles/inserters.cpp

===================================================================

diff --git a/release/scripts/startup/nodes/bparticle_nodes/point_force.py b/release/scripts/startup/nodes/bparticle_nodes/point_force.py
new file mode 100644
index 00000000000..8ed7d4f7a17
--- /dev/null
+++ b/release/scripts/startup/nodes/bparticle_nodes/point_force.py
@@ -0,0 +1,16 @@
+import bpy
+from bpy.props import *
+from .. base import BParticlesNode
+from .. node_builder import NodeBuilder
+
+class PointForceNode(bpy.types.Node, BParticlesNode):
+    bl_idname = "bp_PointForceNode"
+    bl_label = "Point Force"
+
+    def declaration(self, builder : NodeBuilder):
+        builder.fixed_input("direction", "Direction", "Vector", default=(0, 0, -1))
+        builder.fixed_input("strength", "Strength", "Float", default = 1.0)
+        builder.fixed_input("falloff", "Falloff", "Float", default = 1.0)
+        builder.fixed_input("distance", "Distance", "Float", default = 1.0)
+        builder.fixed_input("gravitation", "Gravitation", "Boolean", default=False)
+        builder.particle_modifier_output("force", "Force")
diff --git a/source/blender/simulations/bparticles/forces.cpp b/source/blender/simulations/bparticles/forces.cpp
index 8c2a7db7feb..e6d251fd82e 100644
--- a/source/blender/simulations/bparticles/forces.cpp
+++ b/source/blender/simulations/bparticles/forces.cpp
@@ -40,4 +40,33 @@ void TurbulenceForce::add_force(ForceInterface &interface)
   }
 }
 
+void PointForce::add_force(ForceInterface &interface)
+{
+  ParticlesBlock &block = interface.block();
+  ArrayRef<float3> destination = interface.combined_destination();
+
+  auto inputs = m_compute_inputs->compute(interface);
+
+  for (uint pindex = 0; pindex < block.active_amount(); pindex++) {
+    float3 direction = inputs->get<float3>("Direction", 0, pindex);
+    float strength = inputs->get<float>("Strength", 1, pindex);
+    float falloff = inputs->get<float>("Falloff", 2, pindex);
+    float distance = inputs->get<float>("Distance", 3, pindex);
+    bool gravitation = inputs->get<bool>("Gravitation", 4, pindex);
+
+    if (gravitation) {
+      if (distance < FLT_EPSILON) {
+		strength = 0.0f;
+	  }
+      else {
+        strength *= powf(distance, -2.0f);
+	  }
+	}
+
+    direction *= (strength * falloff);
+
+    destination[pindex] += direction;
+  }
+}
+
 }  // namespace BParticles
diff --git a/source/blender/simulations/bparticles/forces.hpp b/source/blender/simulations/bparticles/forces.hpp
index 1806713752d..0e36a981176 100644
--- a/source/blender/simulations/bparticles/forces.hpp
+++ b/source/blender/simulations/bparticles/forces.hpp
@@ -38,4 +38,17 @@ class TurbulenceForce : public Force {
   void add_force(ForceInterface &interface) override;
 };
 
+class PointForce : public Force {
+ private: 
+  std::unique_ptr<ParticleFunction> m_compute_inputs;
+
+ public: 
+  PointForce(std::unique_ptr<ParticleFunction> compute_inputs)
+      : m_compute_inputs(std::move(compute_inputs))
+  {
+  }
+
+  void add_force(ForceInterface &interface) override;
+};
+
 }  // namespace BParticles
diff --git a/source/blender/simulations/bparticles/inserters.cpp b/source/blender/simulations/bparticles/inserters.cpp
index 53420bf16fb..fecd1f11adc 100644
--- a/source/blender/simulations/bparticles/inserters.cpp
+++ b/source/blender/simulations/bparticles/inserters.cpp
@@ -186,6 +186,14 @@ static std::unique_ptr<Force> BUILD_FORCE_turbulence(
   return std::unique_ptr<Force>(new TurbulenceForce(std::move(compute_inputs_fn)));
 }
 
+static std::unique_ptr<Force> BUILD_FORCE_point(
+    BuildContext &UNUSED(ctx),
+    VirtualNode *UNUSED(vnode),
+    std::unique_ptr<ParticleFunction> compute_inputs_fn)
+{
+  return std::unique_ptr<Force>(new PointForce(std::move(compute_inputs_fn)));
+}
+
 static std::unique_ptr<Event> BUILD_EVENT_mesh_collision(
     BuildContext &ctx, VirtualNode *vnode, std::unique_ptr<ParticleFunction> compute_inputs_fn)
 {
@@ -426,6 +434,7 @@ BLI_LAZY_INIT(StringMap<ForceFromNodeCallback>, get_force_builders)
   StringMap<ForceFromNodeCallback> map;
   map.add_new("bp_GravityForceNode", BUILD_FORCE_gravity);
   map.add_new("bp_TurbulenceForceNode", BUILD_FORCE_turbulence);
+  map.add_new("bp_PointForceNode", BUILD_FORCE_point);
   return map;
 }