Hi all,
I'm building a fictional island for MSFS 2024 — private use, never to be published. It sits in open sea, so unlike a real-world location there is no Bing imagery, no landclass and no elevation data underneath: everything under it is water. I mention this because I suspect several of my problems come from that single fact.
What is in the package right now: 16 terraforming <Rectangle> elements with heightmaps (15 detail ones at ~5 km, plus one 27 × 17 km base at lower priority with a 500 m falloff), a water exclusion polygon (118 km²), a flat-colour CGL underneath, and 112 polygon objects carrying 4 ground materials (grass / rock / sand / soil), each with its own SurfaceType. Vegetation and orthophoto are deliberately switched off — I'm adding one layer at a time so I can tell which one causes what.
What I have already done, so nobody wastes time on the obvious: read the terrain-related SDK pages in full, read Lionel Fuentes' GDC 2022 talk on the terrain system page by page, and searched the forums. The four questions below are the ones where the documentation describes what to write but never states what the engine does.
1. Do the documented material properties apply to Polygon Objects at all?The material pages describe glTF meshes and never say whether the same properties hold for scenery polygons. Concretely: I set MaterialColoration on 74 polygons (verified in the XML: non-zero values, alpha 255 — e.g. RGB 134/103/65 on the soil bands) and the colour on the ground did not change at all, not even at 7 m AGL. Is MaterialColoration expected to work on a Polygon Object, and if so, is there a precondition I'm missing?
2. What is the default of Ground Merging when the attribute is absent from the file?I could not find this stated on any SDK page. It matters a lot in my case: if ground merging is on by default, my materials are blending with the terrain textures underneath — and underneath there is open sea. Could that explain a material that refuses to take a tint?
3. What draws a regular grid of faint lines about 520 m apart on custom terrain?Measured, not estimated: one line sits at longitude 12.7207 and the next crossing at 12.7148, which is ~520 m at this latitude. Three candidates are ruled out by numbers: my heightmap seams (they are 5,020 m apart, ten times wider), the landclass boundary (it lies at 12.6564), and my own polygon edges — a script measuring the distance from the point to every side of every polygon puts the nearest one 250 m away. It isn't the airport ground grid either: the airport doesn't exist yet.The one lead I have doesn't quite fit: a level-16 tile is 488 m at this latitude, and level 16 happens to be the source level of my flat-colour CGL — but 488 is 6.6% off the 520 m I measured, so I don't want to call it a match. Does ~520 m ring a bell for anyone (secondary heightmaps? a streaming or caching grid?), and does the engine draw anything on tile boundaries of its own accord?
4. What actually changes between Terrain Level of Detail 100, 200 and 400 — and do CGL tiles degrade the same way polygons do?The SDK repeats that polygons are baked into the terrain textures and look their best at maximum terrain LOD. I have a hard rule that my scenery must never depend on a setting of 400, since most users sit between 100 and 200. Do custom CGL aerial tiles hold up better than polygons at 100-200, or do both lose detail together?
Any pointer — even a partial one, or a "this is how it behaves in practice" — would save me a lot of blind testing. Happy to share screenshots or the scenery files if useful.
Thanks.
I'm building a fictional island for MSFS 2024 — private use, never to be published. It sits in open sea, so unlike a real-world location there is no Bing imagery, no landclass and no elevation data underneath: everything under it is water. I mention this because I suspect several of my problems come from that single fact.
What is in the package right now: 16 terraforming <Rectangle> elements with heightmaps (15 detail ones at ~5 km, plus one 27 × 17 km base at lower priority with a 500 m falloff), a water exclusion polygon (118 km²), a flat-colour CGL underneath, and 112 polygon objects carrying 4 ground materials (grass / rock / sand / soil), each with its own SurfaceType. Vegetation and orthophoto are deliberately switched off — I'm adding one layer at a time so I can tell which one causes what.
What I have already done, so nobody wastes time on the obvious: read the terrain-related SDK pages in full, read Lionel Fuentes' GDC 2022 talk on the terrain system page by page, and searched the forums. The four questions below are the ones where the documentation describes what to write but never states what the engine does.
1. Do the documented material properties apply to Polygon Objects at all?The material pages describe glTF meshes and never say whether the same properties hold for scenery polygons. Concretely: I set MaterialColoration on 74 polygons (verified in the XML: non-zero values, alpha 255 — e.g. RGB 134/103/65 on the soil bands) and the colour on the ground did not change at all, not even at 7 m AGL. Is MaterialColoration expected to work on a Polygon Object, and if so, is there a precondition I'm missing?
2. What is the default of Ground Merging when the attribute is absent from the file?I could not find this stated on any SDK page. It matters a lot in my case: if ground merging is on by default, my materials are blending with the terrain textures underneath — and underneath there is open sea. Could that explain a material that refuses to take a tint?
3. What draws a regular grid of faint lines about 520 m apart on custom terrain?Measured, not estimated: one line sits at longitude 12.7207 and the next crossing at 12.7148, which is ~520 m at this latitude. Three candidates are ruled out by numbers: my heightmap seams (they are 5,020 m apart, ten times wider), the landclass boundary (it lies at 12.6564), and my own polygon edges — a script measuring the distance from the point to every side of every polygon puts the nearest one 250 m away. It isn't the airport ground grid either: the airport doesn't exist yet.The one lead I have doesn't quite fit: a level-16 tile is 488 m at this latitude, and level 16 happens to be the source level of my flat-colour CGL — but 488 is 6.6% off the 520 m I measured, so I don't want to call it a match. Does ~520 m ring a bell for anyone (secondary heightmaps? a streaming or caching grid?), and does the engine draw anything on tile boundaries of its own accord?
4. What actually changes between Terrain Level of Detail 100, 200 and 400 — and do CGL tiles degrade the same way polygons do?The SDK repeats that polygons are baked into the terrain textures and look their best at maximum terrain LOD. I have a hard rule that my scenery must never depend on a setting of 400, since most users sit between 100 and 200. Do custom CGL aerial tiles hold up better than polygons at 100-200, or do both lose detail together?
Any pointer — even a partial one, or a "this is how it behaves in practice" — would save me a lot of blind testing. Happy to share screenshots or the scenery files if useful.
Thanks.
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