Some track designs can not be placed

[IntelOrca]

Track design does not show any preview and is not placeable. Source: https://www.reddit.com/r/openrct2/comments/4lw871/help_premade_tracks_are_not_working_in/

Track design: No Excitement V3 ChainCableStart_56kmh.zip

[Krutonium]

Anyone know what kind of ride that design is for?

[IntelOrca]

Compact inverted coaster

[IntelOrca]

The issue is with map_can_construct_with_clear_at

The track design intersects itself.

• map_can_construct_with_clear_at ignores ghost elements, thus when the ghost track is placed it does not care that it intersects itself. It therefore wrongly shows that the track is place-able.
• The other problem is that when actually attempting to place the track, it first checks if its possible. This succeeds because it doesn't actually place the track initially causing map_can_construct_with_clear_at to think that the tile containing a previous track piece is free. When actually coming to place the track, it will hit the previously placed track and fail.

The side effect to this is that the ride construction window opens, but the ride is never placed.

So why not just temporarily disable clearance? Because then it will allow you to place the track through other things and not clear trees etc. The whole system for doing this doesn't really allow an easy way to say, oh its fine if it the element is itself.

Current workaround: Disable clearance checks when placing the track.