Switch Development Update – Portals, Backdrop Assets & New Shadowing Techniques

It’s been a while since our last development update, but we’re back to bring you up to speed on what we have been up to these past few weeks!

Backdrop Assets

One of the things we have been working on are the backdrop assets based on this concept rendering using MandelBulb 3D.


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A few weeks ago I created a quick mockup for a portal effect that we could potentially use on switched environment pieces. Here is a short video of the very first results we had last month.

Perhaps the most noticeable issue is the one-frame lag in the portal rendering, this requires a bit more in-depth research to get the update ordering correct since adding tick dependencies had no effect. Getting portal rendering to render and interact flawlessly with the world and players (especially in multiplayer) will take a lot more effort and is not our current focus. We’d like to revisit this feature in the future and see how we could potentially use it in our game.

Release of Unreal 4.5

The new Unreal 4.5 was released last week and we’ve had the pleasure of working with the preview release for some time before that. It’s the biggest patch by Epic yet and included hundreds of fixes and some really great new features. You can read all about it on the official site. We did some testing on a few of the major changes & improvements including Distance Field Ambient Occlusion and the new Ray Traced Distance Field Soft Shadows.

Ambient Occlusion

We’ve tested Distance Field Ambient Occlusion (first introduced in 4.3) to see how it performed in different scenarios and mesh structures. Between the preview and full release of 4.5 they’ve improved upon the effect by adding Specular Occlusion (not shown in comparison) and improved the performance by approx. 20-30%. (Read our full post)

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Soft Shadows

4.5 introduced a new soft shadows technique for fully dynamic lighting (a definite requirement for our constantly changing environment) and it looks amazing, we’ve not done any performance testing ourselves, but according to Epic it’s approx. 20-30% faster than Cascaded shadows maps in most scenarios. (Read our full post)

Unreal engine 4 ray traced distance field soft shadows


UMG (Interface Editor) has been taken out of experimental and is production ready. We’ve started to replace the built-in HUD with some of our own designs. We should have more on that soon.


And finally, we’re continuously making improvements on the switch mechanic itself, trying to get it as fluid as possible during high paced combat. At the same time we’re starting to develop a few new game modes that we expect to start playtesting soon. That is all for this dev update! As usual check out our Facebook page for occasional updates on Switch! Let us know your thoughts and comments below.

Switch Mechanic Quick Look

Further Reading


  1. Thanks for the mention of mandelbulb! Are you just using the concept render as a guide or can you export the meshes?

    You could almost turn that portal lag into a game mechanic if you increased it 🙂 I enjoy reading these updates, Switch is looking good!

    • Thanks Zach! We can’t export it to meshes unfortunately so we rebuild everything from scratch in a modeling app and use this purely for mood and shape reference.

      We’ll keep them coming! It’s serves as a good recap for ourselves too! And I enjoy creating them. 🙂

  2. The portal effect is awesome , without the lag it will be perfect. Also I wanted to know how you made it, I already make the blueprint for the camera replication but I can’t make the texture render work well. Can you help me please?

  3. Nevermind , I figured it out , Its because the resolution of the “new editor window preview” wasn’t the same as the ‘texture render’ of the portal camera. By the way, do you know how to automate this, so the render texture change automaticaly with the window resolution?

    • Didn’t get as far as auto-rescaling of the rendertarget back then. Perhaps all you need is 1 per aspect ratio and swap them in Blueprint based on current resolution.

  4. Hi Tom,

    awesome article!

    I’m currently trying to create portals for a project I’m working on.
    What was your approach? As I can see in the video you setted up a second camera or scene capture which moves relative to the characters position.

    This won’t work for small portal doors right? Because the SceneCap has to be fixed at the portal door location and only rotate with the Look at rotation (Player->Portal Door).
    This is what I’m currently trying to do… works okay-ish for the rotation of the SceneCap and looks good from a distance, but when you come closer it just looks off.
    Maybe I have to adjust the SceneCap height and FOV, but I don’t know how.

    Do you have an idea? I’m stuck here.


    • You need to move the position of the SceneCapture camera too so it doesn’t mess up the perspective and FOV when you get close, the issue that occurs is that the SceneCapture may start clipping with walls etc.

      One thing I did for a more recent implementation with a spherical portal where I smoothly interpolated between a statically captured texture from the environment with the dynamic SceneCapture, any kind of material FX for the static texture would do. With a blend to the dynamic capture only when moving close to the portal, so you never see clipping or strange angles on the portal door.

      – Tom

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