Version: All versions
Frequency: Consistently
Severity: Low
Marketplace package name: KSC Scenery by TerraBuilder
Context: In-sim, rocket launch smoke effects
Similar MSFS 2020 issue: (MSFS2020 VFX Sprite Sorting is broken)
Bug description: This defect report is identical to the one reported for MSFS2020, and we are reporting it again for MSFS2024, since it is a separate platform, for thoroughness. This has been an old defect, going as far back as Microsoft’s FSX from 2006, through P3D (all versions), MSFS2020 and now MSFS2024 - We know because we remember asking about it way back then, without anyone responding. This defect is apparent when a VFX sprite texture contains opaque or near-opaque areas. It seems that, when the emitter is emitting the particles (sprites) away from the observer, the sprite sorting is correct (closer ones are on top of farther ones). However, when the emtter is emitting particles towards the observer, the particles (sprites) are sorted in reverse order - the most distant ones are on top of the closer ones. With the majority of default in-sim VFX, this defect has been diminished by making the default VFX sprites sufficiently transparent so that it is difficult to tell what is in front and what is in the back. However, when the sprite is made more opaque, the defect becomes obvious. While we (at TerraBuilder) understand that most default VFX deal with wispy, transparent, smokey particles and the default VFX work fine for common dust/steam/smoke situations, we are in the process of creating more heavy, thick, well defined smoke particles that require more opaque sprites, and this defect becomes (painfully) more apparent. For example, we have our Kennedy Space Center Scenery title out on Marketplace, and the rocket launching effects (launch pad smoke and rocket smoke trail) look correct only from certain perspectives, while from other perspectives we get the “tunnel” effect, just like in the video. Fixing this defect would GREATLY improve visuals in our case, but would also improve the visuals for any and all add-on products that use smoke trails (airshow), billowing smoke areas (forest fires and volcanoes) and other similar situations.
Repro steps: Create a material with an “orb” sprite PNG with transparency (alpha mask) that has central part opaque, and the fringes transparent. Create a simple emitting VFX (like in the video) and assign a sprite to it. Observe the results, the defect will be similar to the one in the video.
Attachments: We’ve put together a simple VFX that emits sprites and illustrates this defect, and created a video of it. In the video, the sprite is emitted from the rear of the aircraft (on ground). With the emitter emitting away from the observer, everything looks good, however, as the camera pans around the scene, the observers is put farther back from the aircraft, looking towards it and towards the effect. From this vantage point, the emitter is emitting particles TOWARDS the observer, and the defect becomes apparent at time index 00:50. The video is made in MSFS2020 but the same defect is observed in MSFS2024.
Best regards,
Mitch
TerraBuilder team