Outerra forum

Outerra Engine => Technology => Topic started by: Steve.Wilson on September 07, 2014, 11:50:23 am

Title: Using Outerra as a View System - Apples and Oranges
Post by: Steve.Wilson on September 07, 2014, 11:50:23 am
When I first became interested in Outerra, I almost immediately began to wonder how to merge the technical excellence of X-Plane's systems and flight model with the visual beauty of Outerra.  Not too very long after that, Cameni announced the means to use Outerra as a visual engine for other simulations, that is, simulations running separately, just using Outerra to present the world.

The problem with that, as mentioned before, is the difficulty of synchronizing terrain interaction.  Both aircraft and world simulations would be using different terrain meshes, apples and oranges.  This isn't a big deal in flight, and if one were flying a dirigible or a blimp, no problem.  But when it comes time for aircraft landing gear to "touch down," in some cases the gear is going to sit on thin air, sometimes the aircraft could be buried up to the windscreen, or worse! 

An enterprising fellow using X-Plane recently accomplished the feat of using Mars MOLA data to create an X-Plane 10 compatible terrain mesh for Mars.  The terrain overlays the whole planet, and is deployed as "custom scenery" in the same way that another fellow deploys high resolution Earth terrain for X-Plane of his own creation.  This got me thinking about terrain meshes again, and the solution to the apples and oranges problem of using Outerra as a visuals engine for X-Plane became clear! 

I wonder if it would be possible to use the Outerra terrain mesh as a resource to generate an identical terrain mesh for X-Plane 10 that would be deployed as X-Plane "custom scenery," thus permitting coincident runways and terrain that aircraft could land on and be visually in near perfect contact with the ground.

X-Plane terrain generation tools are available to generate terrain meshes from text data.  The only thing left is to acquire the means to somehow read the Outerra terrain mesh, and to convert it to text readable terrain tiles that could be translated into a form that the X-Plane terrain tools could use.

How much of a challenge might this be?  That's the final thing to wonder.  What do the Outerra intelligentsia think of this?

(Note:  This requires two PC's for one simulation, one running Outerra, the other X-Plane, networked via X-Plane plugin and the Outerra external view capability).
Title: Re: Using Outerra as a View System - Apples and Oranges
Post by: cameni on September 07, 2014, 12:35:17 pm
What is the resolution and projection of terrain meshes that X-Plane accepts? I guess it will have to be reprojected from OT's internal projection.

One problem is that it's very easy to modify terrain in OT by vector data, an operation that's applied on terrain in run time, not baked into the terrain data. It would have to be collapsed and the data would be valid for given snapshot of world only.
Title: Re: Using Outerra as a View System - Apples and Oranges
Post by: Steve.Wilson on September 07, 2014, 01:22:13 pm
Brano, I was aware of the ability to dynamically modify OT terrain in run time.  This becomes of modest concern with runway heights, I think, so there may need to be "negotiation" there to some extent.  However, since the runways won't change from run to run, it should be possible to use the vector data used to alter terrain as reference data when creating corresponding airport runways and tarmacs in X-Plane.  That way those would agree.  As for the rest of the terrain, it wouldn't be possible to land on roads, but it should be possible to land on the raw world terrain, since I suspect that is less likely to be modified by vector.

As to your first question, I don't know.  The interesting thing is that this appears to be somewhat dynamic, driven by the source material.  X-Plane ships with about 70gb of terrain, but that's an artificial limit imposed by how much Laminar Research can fit on a fixed number of DVD's.  The so-called "High Definitiion Terrain" that is available for download via torrent is much larger, and as a result, much smoother in terms of appearance.

I have to admit, I'm not a terrain guy.  I'm just starting a conversation.  But I think that your assessment, if I understand it correctly, would be to simply reproject the OT terrain's vertices and polygons as text that could be reformatted into the text terrain format of X-Plane.  Is this a big challenge?
Title: Re: Using Outerra as a View System - Apples and Oranges
Post by: cameni on September 07, 2014, 02:33:05 pm
Seeing DSF Usage In X-Plane (http://developer.x-plane.com/?article=dsf-usage-in-x-plane) it definitely needs reprojection to geographic coordinates. That's more complicated, basically needs to reverse the terrain import process, with extra generated steps. Also, X-Plane formats are pretty blown up, generating OT data in that will result in a quite large dataset.

It's doable, but not simple.
Title: Re: Using Outerra as a View System - Apples and Oranges
Post by: Steve.Wilson on September 07, 2014, 03:01:13 pm
Doable is good, complex not so much.  Not something I would think of as a project for "right now," but I did think the concept worth exploring, unless the clouds part and all of sudden X-Plane ends up looking amazing from extreme altitude.  Which it does not, and I rather like flying where the air is quite thin.  :) 

Should some other eager individual see this as a fun challenge, I'll consider the idea tabled for now, Brano.  But thanks for answering the basic question!
Title: Re: Using Outerra as a View System - Apples and Oranges
Post by: Steve.Wilson on September 20, 2014, 04:39:34 pm
An epiphany.  I would still like to pursue converting the Outerra terrain mesh to X-Plane at some point to facilitate off field landings for bush, helicopter and sailplane pilots.

However, it strikes me that I don't need the whole world!  As long as an airport in Outerra is point for point identical to an airport in X-Plane, then there should be, in theory, no reason for an aircraft sitting on the ground in X-Plane to not appear completely at home on the ground in Outerra.  And it's got to be a LOT easier to replicate an Outerra airfield in X-Plane than the entire global terrain mesh!  That is the interim goal now, and worth moving forward on in some way.

I just need to get smart on how airfields are made in Outerra so I can make the same airport in X-Plane.

And ....I think I also need to learn how to use Outerra as a view system.  I was unsure of this before, but now I'm certain that I'll be using Outerra for all of my flight sim view needs.  I'm just so deathly sick of flying around in a polygonish landscape when so much beauty can be had in the Anteworld environment.