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"

How do you build lighting for mobile preview?

So, if you switch the render settings to anything below shader model 5, the build button gets greyed out.

I'm using a scene where there's no dynamic lighting, all lighting are set to static. All directional lights. (only 2 on the map)

If I switch this to html5 mobile preview, the map turns dark and the "Lighting needs to be rebuilt (X unbuilt lighting)" red text alert is displayed on screen. It doesn't go away even if you build and deploy to a smartphone.

How do you build lighting if the build lighting button is greyed out?

Product Version: UE 4.19 Preview
more ▼

asked Jan 26 '18 at 08:03 AM in Rendering

avatar image

171 20 27 41

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

2 answers: sort voted first


Thank you for the report. Unfortunately, this action is by default. While hovering over the "Build Lighting Only" in the drop down arrow next to "Build," it states, "Only precomputes lighting (All Levels). This action is not available while Play in Editor is active, or when previewing less than Shader Model 5." The resolution I found to this works quite fast.

The first time the rendering options is changed to Mobile HTML5 Preview, the project will take a while to compile all the shaders and everything in the project. However, this is the only time it will take a while (the next time the rendering options is changed from one option to another it should be pretty much an instant change). With this said, before the rendering options are changed to, for example, Mobile HTML5 Preview the lighting should be built in normal Shader Model 5. If you're adding and making changes to the project in Mobile HTML5 Preview, switch back to Shader Model 5 once ready and build the lighting, then return to Mobile HTML5 Preview as needed.

I hope this information finds you well. If there is anything that I can help you with please do not hesitate to reply.

Best Regards,


more ▼

answered Jan 26 '18 at 08:05 PM

avatar image

Natalia Q ♦♦ STAFF
565 2 3 3

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

@Natalia Do all ue4 developers develop mobile games this way?

more ▼

answered Mar 08 '19 at 01:24 PM

avatar image

1 2

(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