Adjust radiance field tutorial to new integrator API

Author: dvicini

inverse_rendering/radiance_field_reconstruction.ipynb

@@ -310,7 +310,7 @@
     "            t += step_size\n",
     "            active &= (t < maxt) & dr.any(dr.neq(β, 0.0))\n",
     "\n",
-    "        return L if primal else δL, mi.Bool(True), L\n",
+    "        return L if primal else δL, mi.Bool(True), [], L\n",
     "\n",
     "    def traverse(self, callback):\n",
     "        callback.put_parameter(\"sigmat\", self.sigmat.tensor(), mi.ParamFlags.Differentiable)\n",