Search in
Sort by:

Question Status:

Search help

  • Simple searches use one or more words. Separate the words with spaces (cat dog) to search cat,dog or both. Separate the words with plus signs (cat +dog) to search for items that may contain cat but must contain dog.
  • You can further refine your search on the search results page, where you can search by keywords, author, topic. These can be combined with each other. Examples
    • cat dog --matches anything with cat,dog or both
    • cat +dog --searches for cat +dog where dog is a mandatory term
    • cat -dog -- searches for cat excluding any result containing dog
    • [cats] —will restrict your search to results with topic named "cats"
    • [cats] [dogs] —will restrict your search to results with both topics, "cats", and "dogs"

WorldToMeterScale does not work properly with Vive and Asynchronous Reprojection

I found an error where for some frames the default value of 100 is taken for the WorldToMeterScale, even if the value has been changed. This error occurs for scenes where the render time takes sometimes slightly more and sometimes slightly less than the required time to hit 90 fps (~11ms). And only if it is tested with Vive and Asynchronous Reprojection enabled. The effect of this error is that the camera seems to jump around very fast as it is sometimes scaled with the changed WorldToMeterScale and sometimes with the default value.

The error can be reproduced with the following steps:

  1. Create new Project in Unreal Engine 4.18.1 with the Blueprint VR Template

  2. Open VirtualRealityBP/Blueprints/MotionControllerPawn Blueprint

  3. Add "Set World to Meter Scale" Node between EventBeginPlay and Seq

  4. Set "New Scale" to 10

  5. Compile and Save Blueprint

  6. Open VirtualRealityBP/Maps/MotionControllerMap

  7. Add enough objects to the scene that your computer isnt able to render it at 90+ fps anymore (For my setup I added 500 SM_TableRound and 2500 SM_Chairs from the Starter Content folder to the scene)

  8. Test scene in VR with Vive and Asynchronous Reprojection on

  9. Look around and find a position where some frames are rendered in the required time to hit 90 fps and some take a bit longer.

Product Version: UE 4.18
more ▼

asked Nov 27 '17 at 11:10 AM in Bug Reports

avatar image

6 1 6

avatar image Rudy Q ♦♦ STAFF Nov 30 '17 at 07:08 PM

Hello BSteger,

I have run a few tests on our end. I was unable to reproduce this issue with the information provided. Could you provide a project that is experiencing this issue so that I can take a closer look (along with any steps needed to reproduce the issue in the project provided)? Could you also elaborate further on what exactly it is that you are seeing when the issue occurs?

avatar image BSteger Dec 01 '17 at 09:59 AM

Hi Rudy,

Thanks for the reply. I uploaded a video to showcase the effect of the issue https://www.youtube.com/watch?v=dOUQYOes-j0 . The effect is best visible at around 0:34. For some reason the WorldToMeterScale gets reset to 100 for the interleaved frames causing the camera to jump to a different location. I created a project with the 9 steps listed above, but its about 600mb big. Whats the best way to share it with you?

avatar image Rudy Q ♦♦ STAFF Dec 08 '17 at 08:15 PM

You can provide the project via a google drive or drop box link.

avatar image BSteger Dec 11 '17 at 09:52 AM

I uploaded it to Google Drive https://drive.google.com/open?id=1ww252-XU26UyuMn_1dkH2yW63UOWSOVc The computer I tested it has a GeForce 1070, if you have a different GPU you probably need to adjust the scene to get the same frame timing as in the video.

(comments are locked)
10|2000 characters needed characters left
Viewable by all users

1 answer: sort voted first


We've recently made a switch to a new bug reporting method using a more structured form. Please visit the link below for more details and report the issue using the new Bug Submission Form. Feel free to continue to use this thread for community discussion around the issue.



more ▼

answered May 24 '18 at 07:35 PM

avatar image

Rudy Q ♦♦ STAFF
47.4k 545 132 524

(comments are locked)
10|2000 characters needed characters left
Viewable by all users
Your answer
toggle preview:

Up to 5 attachments (including images) can be used with a maximum of 5.2 MB each and 5.2 MB total.

Follow this question

Once you sign in you will be able to subscribe for any updates here

Answers to this question