Comments on: DSF Recuts – Some Basics

By: Ben Supnik

Ben Supnik — Thu, 11 Apr 2013 17:53:11 +0000

In reply to Andrew. We don't show dams right now.

By: Andrew

Andrew — Thu, 11 Apr 2013 04:29:13 +0000

Will a dam in OSM show up in X-Plane or is it just rivers and lakes?

By: PGrGr

PGrGr — Wed, 10 Apr 2013 14:40:09 +0000

In reply to Ben Supnik. Thanks for that, Ben. I applaud you for not just writing an interesting blog, but for engaging in dialogue with us lot. Its refreshing to get personal responses from a company distributing a mass, worldwide product.

By: Alpilotx

Alpilotx — Tue, 09 Apr 2013 20:14:40 +0000

In reply to Julio Campa. I do not want to promise to much, or jump the gun ... but a test with Rio showed (after changing elevation data source) that it has vastly improved (yes, I know how bad the original XP10 version looks).

By: Ben Supnik

Ben Supnik — Tue, 09 Apr 2013 20:02:39 +0000

In reply to Cormac.

Well, the border-handling algorithm is changing….so…it probably won’t have a fit, but more notes coming soon.

By: Cormac

Cormac — Tue, 09 Apr 2013 19:36:00 +0000

“…Due to a last-minute data screw-up by me, many airports in the original DSFs were cut with very old airport data …”
U-huh! Guessed as much when I discovered that the boundary data that I had submitted for all Irish airports ahead of Robin’s deadline was not reflected in the v10 DSF cut. I also notice that the edge of the airfield ground texture can be somewhat soft/blended. In some of the small grass strips I’ve submitted (and no doubt others), the boundary is wrapped fairly tightly around the runway(s), within maybe 2-3 metres at times. This reflects real world cases where the runway may just be a stretch of grass inside an electric fence in the middle of an agricultural field. Will the algorithm throw a hissy fit at this? An example would be EIKH.
(and if you have to recut the Irish tiles sooner rather than later to test this, so be it, there’s lots of updated OSM data there too 😉 )

By: Ben Supnik

Ben Supnik — Tue, 09 Apr 2013 19:35:15 +0000

In reply to mattp.

I’m not sure – we’d have to try it. But my guess is that the patches will be low efficiency — final DSFs are heavily bit-packed and even small changes in source data can ripple through and bit-pattern changes in the entire file.

Jonathan Morton used deltas on the v6 ENVs to make a patched update cheap to download, but ENVs are a much simpler format and the data changes were localized (in a format where the locality was preserved).

By: mattp

mattp — Tue, 09 Apr 2013 19:29:38 +0000

Are differential file patches unworkable for DSFs? I’m assuming the algorithms used to convert the various geo data sources (including OSM) need a clean run at tile generation and the differences between old and new so great that diffing isn’t an option? It’d be ideal if the update engine didn’t need to replace entire DSF tiles that have changed but I can see why it needs to.

By: Ben Supnik

Ben Supnik — Tue, 09 Apr 2013 01:54:39 +0000

In reply to PGrGr.

I can’t go into it in a ton of detail now. But basically what I am saying is that:
– The osm2xp facades are higher in accuracy – with osm2xp the building follows the shape the data dictates to the maximum extent.
– The v10 autogen is much looser in placement, but higher in visual detail – you have driveways connecting houses to the sidewalks and buildings that form complete blocks with no ‘wasted’ space.

So it’s a trade-off – there isn’t a right or wrong. The LR approach (autogen) makes sense for what we try to solve with the global scenery.

It was an intentional design decision of the scenery system that the global scenery is NOT the only way that OSM data (or any data) can be brought into the scenery system; the scenery system is very flexible and can do lots of things that we (LR) will never do with it.

By: Ben Supnik

Ben Supnik — Tue, 09 Apr 2013 01:47:33 +0000

In reply to Bob Marsh. The exclusion zone should remove hard surfaces. Please file a bug - attach a MINIMAL scenery pack that can repro this (it should literally just take one exclusion zone) and the runway/taxiway to drive on.