In UE 4.25, I have gotten all sorts of crashes while editing materials (specifically around blending landscape layers). Most recently it has been when trying to pass landscape coords to the input of a material function. I have enabled “use material attributes” in my project settings, and I am trying to build my landscape material. My general approach has been to define a material function that takes in landscape coordinates and outputs a material, define a function instance for each layer, then use landscape layer blend to combine them for the final output. As far as I can tell, this is a supported approach.
Could someone please advise on how to either troubleshoot this, work around it, or the roadmap for a fix? It is currently blocking my landscape creation workflow.
Reproduction Steps
- Set up a landscape layer material function like so:
- Configure an instance of that function for your bedrock layer:
- To test the general concept, create a material that passes landscape layer coords to that instance:
For me, this reliably causes a crash with the following crash report:
LoginId:1545bb5b4fa809ff9f00dcb21d814b7e
EpicAccountId:cf2daa7395b84a71a1d4575e62c15e82
Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\Build\++UE4+Licensee\Sync\Engine\Source\Runtime\Core\Public\Containers/Array.h] [Line: 674] Array index out of bounds: 12 from an array of size 12
UE4Editor_Core
UE4Editor_Core
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_UnrealEd
UE4Editor_MaterialEditor
UE4Editor_MaterialEditor
UE4Editor_MaterialEditor
UE4Editor_UnrealEd
UE4Editor_GraphEditor
UE4Editor_GraphEditor
UE4Editor_Slate
UE4Editor_Slate
UE4Editor_Slate
UE4Editor_Slate
UE4Editor_Slate
UE4Editor_ApplicationCore
UE4Editor_ApplicationCore
UE4Editor_ApplicationCore
UE4Editor_ApplicationCore
user32
user32
UE4Editor_ApplicationCore
UE4Editor
UE4Editor
UE4Editor
UE4Editor
UE4Editor
kernel32
ntdll
Crash dump attached:
[crash dump][4]