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"

Difficulty with RebuildLightMaps

So I've been attempting to set up an automated system that'll rebuild the lighting in our project. However, I've been having some trouble getting RebuildLightMaps to work correctly.

If I use the following command via a build tool that I've set up:

 D:\P4\WorkSpace\Engine\Build\BatchFiles\RunUAT.bat RebuildLightMaps -project=.\GameFolder\Game.uproject -platform=Win64 -quality=Preview

I get the following error and stack trace:

 Log.WriteException: BuildException: No target name was specified on the command-line.
 Log.WriteException:    at UnrealBuildTool.TargetDescriptor.ParseCommandLine(String[] Arguments, Boolean bUsePrecompiled, Boolean bSkipRulesCompile, FileReference& ProjectFile) in D:\P4\WorkSpace\Engine\Source\Programs\UnrealBuildTool\Configuration\TargetDescriptor.cs:line 207
 Log.WriteException:    at UnrealBuildTool.UnrealBuildTool.RunUBT(BuildConfiguration BuildConfiguration, String[] Arguments, FileReference ProjectFile, Boolean bCatchExceptions) in D:\P4\WorkSpace\Engine\Source\Programs\UnrealBuildTool\UnrealBuildTool.cs:line 1136

I'm unsure what exactly its looking for, as I think i've followed the examples I've seen online, but they might have been for older versions of the engine. Adding a -TargetType=Program, ie, the argument it seems to be looking for according to the code in the stack trace, doesn't seem to affect this error.

Is there an example of this command in use anywhere, or is there something obvious that I've left out? I believe my paths are right, given that other commands via our build tool work fine for the files, but I don't know what else I could be missing.

Product Version: UE 4.21
more ▼

asked Feb 05 '19 at 03:05 PM in Using UE4

avatar image

10 4 6 7

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

1 answer: sort voted first

So I went and read the code for the command, thinking perhaps that I'd forgotten to add a parameter, and it turns out I had. You need to give it the parameter -CommandletTargetName=UnrealLightMass, and also -Submit as it will fail to submit to perforce otherwise.

Hopefully this'll appear somewhat highly in results for this subject, so you should also know that the command will fail outright if one of the maps you're trying to build is unable to be accessed. We have exclusive checkout of .umap assets, so I was hoping it would just skip over the map and let you know in the log it had done so, but unfortunately not.

more ▼

answered Feb 06 '19 at 10:36 AM

avatar image

10 4 6 7

(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