context
For all the years I've used create, the flywheel:instanced backend has given me trouble. I've always gotten around this by switching to flywheel:batching, but as that backend no longer seems to exist I was searching through both the issue trackers for both flywheel and create in hopes of finding a new workaround. I sort of assumed whatever my problem might be would have been reported at some point, but since none of the screenshots I saw looked quite the same as what I've experienced it sort of falls on me to to isolate and document the bug and report it properly. After asking the create discord which github would be most appropriate they pointed me here. Note that while I'm limiting this report to a single stripped-down instance for clarity I have observed this same behavior across many versions of minecraft, multiple modloaders (I've definitely seen it on forge; I can't recall whether it happened on fabric), both standalone and bundled flywheel, multiple macOS versions, and multiple JVMs (here I used OpenJDK but it also happens on GraalVM).
environment
laptop model: MacBook Pro 15-inch, 2018
CPU: 2.6 GHz 6-Core Intel Core i7
GPU: Radeon Pro Vega 20
OS: macOS Sequoia 15.7.4
JVM: Microsoft OpenJDK 64-Bit Server VM 21.0.7+6-LTS
minecraft version: 1.21.1
neoforge version: 21.1.228
modlist:
reproduction / description
The fastest way to reproduce the bug I've found is to render a train bogey, at which point the game screeches to a halt for multiple seconds before finally producing visuals with what seems to be misplaced triangles. In the void world I used to record the bug the results were fairly tame, but when actual terrain is involved I've seen things get quite spicy (repeated grids of triangles that move out of sync with the rest of the world, triangles either drawn over or cut out from the model being rendered, and a noticeable degradation to performance; normally the visuals are fairly stable even while translating/rotating perspective, not the exploding triangles that you sometimes see with graphical bugs). This has only ever occurred when using the instanced backend.
demo / logs
I've included a demonstration and the logs that accompany it. Note that I've cut about 40 seconds of the freeze when placing the bogey out of the video to save you some time and cut down on file-size.
flywheel_bug_demo.mov
flywheel_bug_demo.log
context
For all the years I've used create, the flywheel:instanced backend has given me trouble. I've always gotten around this by switching to flywheel:batching, but as that backend no longer seems to exist I was searching through both the issue trackers for both flywheel and create in hopes of finding a new workaround. I sort of assumed whatever my problem might be would have been reported at some point, but since none of the screenshots I saw looked quite the same as what I've experienced it sort of falls on me to to isolate and document the bug and report it properly. After asking the create discord which github would be most appropriate they pointed me here. Note that while I'm limiting this report to a single stripped-down instance for clarity I have observed this same behavior across many versions of minecraft, multiple modloaders (I've definitely seen it on forge; I can't recall whether it happened on fabric), both standalone and bundled flywheel, multiple macOS versions, and multiple JVMs (here I used OpenJDK but it also happens on GraalVM).
environment
laptop model:
MacBook Pro 15-inch, 2018CPU:
2.6 GHz 6-Core Intel Core i7GPU:
Radeon Pro Vega 20OS:
macOS Sequoia 15.7.4JVM:
Microsoft OpenJDK 64-Bit Server VM 21.0.7+6-LTSminecraft version:
1.21.1neoforge version:
21.1.228modlist:
6.0.10)reproduction / description
The fastest way to reproduce the bug I've found is to render a train bogey, at which point the game screeches to a halt for multiple seconds before finally producing visuals with what seems to be misplaced triangles. In the void world I used to record the bug the results were fairly tame, but when actual terrain is involved I've seen things get quite spicy (repeated grids of triangles that move out of sync with the rest of the world, triangles either drawn over or cut out from the model being rendered, and a noticeable degradation to performance; normally the visuals are fairly stable even while translating/rotating perspective, not the exploding triangles that you sometimes see with graphical bugs). This has only ever occurred when using the instanced backend.
demo / logs
I've included a demonstration and the logs that accompany it. Note that I've cut about 40 seconds of the freeze when placing the bogey out of the video to save you some time and cut down on file-size.
flywheel_bug_demo.mov
flywheel_bug_demo.log