[PlanarReflection] Update capture frustrum calculation

ScriptableRenderPipeline/Core/CoreRP/Editor/CameraEditorUtils.cs

             return true;
         }
 
+        public static Matrix4x4 GetCameraClipToWorld(
+            Vector3 position, Quaternion rotation,
+            float nearClipPlane, float farClipPlane,
+            float fov, float aspect)
+        {
+            var p = Matrix4x4.Perspective(fov, aspect, nearClipPlane, farClipPlane);
+            var v = Matrix4x4.TRS(position, rotation, new Vector3(1, 1, -1)).inverse;
+            var vp = p * v;
+            var clipToWorld = vp.inverse;
+            return clipToWorld;
+        }
+
+        public static Vector3 PerspectiveClipToWorld(Matrix4x4 clipToWorld, Vector3 viewPositionWS, Vector3 positionCS)
+        {
+            var tempCS = new Vector3(positionCS.x, positionCS.y, 0.95f);
+            var result = clipToWorld.MultiplyPoint(tempCS);
+            var r = result - viewPositionWS;
+            return r.normalized * positionCS.z + viewPositionWS;
+        }
+
+        public static void GetFrustrumPlaneAt(Matrix4x4 clipToWorld, Vector3 viewPosition, float distance, Vector3[] points)
+        {
+            points[0] = new Vector3(-1, -1, distance); // leftBottomFar
+            points[1] = new Vector3(-1, 1, distance); // leftTopFar
+            points[2] = new Vector3(1, 1, distance); // rightTopFar
+            points[3] = new Vector3(1, -1, distance); // rightBottomFar
+            for (var i = 0; i < 4; ++i)
+                points[i] = CameraEditorUtils.PerspectiveClipToWorld(clipToWorld, viewPosition, points[i]);
+        }
+
         static Vector3 MidPointPositionSlider(Vector3 position1, Vector3 position2, Vector3 direction)
         {
             Vector3 midPoint = Vector3.Lerp(position1, position2, 0.5f);

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/Lighting/PlanarReflectionProbeUI.Handles.cs

 
         static void DrawGizmos_CaptureFrustrum(PlanarReflectionProbeUI s, PlanarReflectionProbe d)
         {
-            var farClipPlane = d.captureFarPlane;
-            var nearClipPlane = d.captureNearPlane;
-            var mat = Matrix4x4.TRS(d.capturePosition, d.captureRotation, Vector3.one);
+            var clipToWorld = CameraEditorUtils.GetCameraClipToWorld(
+                d.capturePosition, d.captureRotation,
+                d.captureNearPlane, d.captureFarPlane,
+                90, 1);
-            far[0] = new Vector3(0, 0, farClipPlane); // leftBottomFar
-            far[1] = new Vector3(0, 1, farClipPlane); // leftTopFar
-            far[2] = new Vector3(1, 1, farClipPlane); // rightTopFar
-            far[3] = new Vector3(1, 0, farClipPlane); // rightBottomFar
-            for (var i = 0; i < 4; ++i)
-                far[i] = mat.MultiplyPoint(far[i]);
-            near[0] = new Vector3(0, 0, nearClipPlane); // leftBottomNear
-            near[1] = new Vector3(0, 1, nearClipPlane); // leftTopNear
-            near[2] = new Vector3(1, 1, nearClipPlane); // rightTopNear
-            near[3] = new Vector3(1, 0, nearClipPlane); // rightBottomNear
-            for (var i = 0; i < 4; ++i)
-                near[i] = mat.MultiplyPoint(near[i]);
+            CameraEditorUtils.GetFrustrumPlaneAt(clipToWorld, d.capturePosition, d.captureFarPlane, far);
+            CameraEditorUtils.GetFrustrumPlaneAt(clipToWorld, d.capturePosition, d.captureNearPlane, near);
 
             var c = Gizmos.color;
             Gizmos.color = k_GizmoCamera;
                 Gizmos.DrawLine(far[i], far[(i + 1) % 4]);
                 Gizmos.DrawLine(near[i], far[i]);
             }
+
+            Gizmos.DrawSphere(d.capturePosition, HandleUtility.GetHandleSize(d.capturePosition) * 0.2f);
             Gizmos.color = c;
         }
     }