Add shadow point to all shapes

Author: dvicini

src/shapes/bsplinecurve.cpp

@@ -1006,6 +1006,7 @@ class BSplineCurve final : public Shape<Float, Spectrum> {
         si.prim_index = pi.prim_index;
         si.shape = this;
         si.instance = nullptr;
+        si.p_shadow = si.p;
 
         return si;
     }

src/shapes/cylinder.cpp

@@ -758,6 +758,7 @@ class Cylinder final : public Shape<Float, Spectrum> {
         si.prim_index = pi.prim_index;
         si.shape    = this;
         si.instance = nullptr;
+        si.p_shadow = si.p;
 
         return si;
     }

src/shapes/disk.cpp

@@ -513,6 +513,7 @@ class Disk final : public Shape<Float, Spectrum> {
         si.prim_index = pi.prim_index;
         si.shape    = this;
         si.instance = nullptr;
+        si.p_shadow = si.p;
 
         return si;
     }

src/shapes/ellipsoids.cpp

@@ -391,6 +391,7 @@ class Ellipsoids final : public Shape<Float, Spectrum> {
         si.prim_index = pi.prim_index;
         si.shape      = this;
         si.instance   = nullptr;
+        si.p_shadow   = si.p;
 
         return si;
     }

src/shapes/ellipsoidsmesh.cpp

@@ -309,6 +309,7 @@ class EllipsoidsMesh final : public Mesh<Float, Spectrum> {
 
         // Divide by the number of faces per Gaussians
         si.prim_index /= (uint32_t) m_shell_faces.size();
+        si.p_shadow = si.p;
 
         return si;
     }

src/shapes/instance.cpp

@@ -190,6 +190,7 @@ class Instance final: public Shape<Float, Spectrum> {
 
         // Hit point `si.p` is only attached to the surface motion
         si.p = to_world * si.p;
+        si.p_shadow = to_world * si.p_shadow;
         si.n = dr::normalize(dr::detach(to_world) * si.n);
         if (likely(has_flag(ray_flags, RayFlags::ShadingFrame)))
             si.sh_frame.n = dr::normalize(dr::detach(to_world) * si.sh_frame.n);

src/shapes/linearcurve.cpp

@@ -364,6 +364,7 @@ class LinearCurve final : public Shape<Float, Spectrum> {
         si.prim_index = pi.prim_index;
         si.shape    = this;
         si.instance = nullptr;
+        si.p_shadow = si.p;
 
         return si;
     }

src/shapes/sdfgrid.cpp

@@ -451,6 +451,7 @@ class SDFGrid final : public Shape<Float, Spectrum> {
         si.prim_index = pi.prim_index;
         si.shape    = this;
         si.instance = nullptr;
+        si.p_shadow = si.p;
 
         return si;
     }

src/shapes/sphere.cpp

@@ -735,6 +735,7 @@ class Sphere final : public Shape<Float, Spectrum> {
         si.prim_index = pi.prim_index;
         si.shape    = this;
         si.instance = nullptr;
+        si.p_shadow = si.p;
 
         return si;
     }