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Mirror Rendering with Planar Reflection drops the FPS

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    Originally posted by mariomguy View Post
    Planar maps do not have occlusion culling, they are only culled by the view of the object bounds. So by having 3 planar maps in view, even if they're occluded by walls and other objects, your scene is being rendered 6 times.
    This is not true. Planar reflection capture do use occlusion queries just like the main view does. Planar actor is also occlusion tested as if it's occluded reflection pass can be skipped completely.

    But precomputed visibility is broken with planar reflections and that has to be disabled manually to avoid some missing reflectors.


      Originally posted by CarloAlt View Post
      I have a room with 3 PR
      If two or more PR's are visible at the same time you will tank your performance, there is a note about this on the documentation page that says:

      If at all possible limit the amount of Planar Reflection Actors placed in the world to only one and move, rotate, or scale it to best fit the world. While you can use multiple Planar Reflection Actors, you need to exercise caution as Planar Reflection Actors do not do any sort of distance culling, only frustum, and occlusion culling. Because of this if both Planar Reflection Actors are in view at the same time your project's frame rate will suffer severely.
      That's probably why you are experiencing performance issues.

      Have you already looked into using SceneCapture2D actors for the mirrors instead? Might be worth trying
      Last edited by DotCam; 06-21-2018, 10:32 AM.
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        I have made optimizations and fixes for planar reflections. These should help a lot when you are trying to use multiple small planar reflection actors.


          Originally posted by Kalle_H View Post
          Use "Show Only Actors" feature and then only add actors inside that room and player. Also make system where you set planar reflections visible toggle false when you are not in the room.
          How do you add the player? Since the player isn't in the World Outliner I can't pick it from the list. I tried adding an instance of the character BP but that didn't work because when you spawn with player start it's adding the character to the level dynamically.
          Last edited by TorQueMoD; 12-23-2019, 01:16 AM.


            I've since discovered that you can add your player character into the map and set the Auto Possess to Player 0 and it will work when you then select the player character in the world outliner and add it to the planar reflection's included list.