Handling OmnidirectionalSightline Implementations

[mandretis]

Hello.

I have created a 360 Line of sight implementation based on the 'OmnidirectionalSightline' class.
i have 2 Questions.

1. Although it works quite well in 3d, when visualizing on 2d the shape is indicating full vision-LOS as if it doesn't take elevation/terrain into account (No occlusion at all). How can i have visibility information on 2d ?

2. LOS-Occlusion visualization seems to change as i zoom- in/zoom-out which should normally remain the same. Is there a way elevation can be fully loaded beforehand for the inputs of center,range and height so that it doesn't get affected by zooming?

version 1.4.0

Kind Regards.

[EMaksymenko]

This feature is based on shadows, and in 2D we do not render terrain elevations, so this feature will not work in 2d.

Elevations change from distance for performance reasons. You can try to decrease detailControl in BasicTessellator and the sightline will be more detailed, but performance will drop.

This feature is purely runtime, so it is not possible to store the most detailed elevations inside the circle.

[mandretis]

Thank you for your quick answer.

There isn't possibly a way to manually apply shadows on 2d right ?

I'm trying to think of a work-around for this, even if the result is just a circle with some polygons inside.

[chaniotisalex]

Hello,

A work-around for this is to remove the below line from TerrainTile.kt and rebuild the library locally.

WorldWindKotlin/worldwind/src/commonMain/kotlin/earth/worldwind/globe/terrain/TerrainTile.kt

Line 49 in 8d93fe8

heightGrid.fill(0f) // Do not show terrain in 2D, but keep height values in vertex for heatmap

This will cause 2D to show/ take into account the terrain data, as seen below:

[EMaksymenko]

Yes, but all other things like Shapes also draws flat in 2d node. It is by design.

Why do not you just use 3D with tilt = 0 instead of 2D?

This is intentionally switched off. You need a separate feature made with another approach like elevation heatmap.