Re: photo

On Wed, 31 Dec 2003, David Luff wrote:

> Hi Jon,
>
> I've never tried playing with the specific photo-scenery creator, so I

The photo program works in a similar way to genapts - it creates an
seperate btg file, and a hole definition for the standard scenery.

> can't comment on the differences between that and normal scenery
> generation, but I have draped small areas of photos over the scenery
> using the normal tools before.  As you say, defining a polygon with a
> custom name, and then defining the texture for that name to be the
> photo, works just fine.  By default, the orientation of the texture is
> Northwards (I think) so most photos come out fine.

Excellent, I'll give it a try.

> There's a couple of undocumented helpers available for the UK though.
> If you give your polygons the extension .osgb36 then the coords will
> (should!) be interpreted as UK eastings and northings (meters) so eg you
> could have a polygon file:
>
> CUSTOM_PHOTO_1
> 1
> 430000 300000
> 431000 300000
> 431000 301000
> 430000 301000
> 430000 300000

How handy :-)

> Not sure of the exact format there, but you get the gist, it's much
> easier to use eastings and northing for UK photos cut up along the grid
> than to convert to lat, lon.
>
> However, the texture scaling is still based on lat, lon, so the textures
> have a discontinuity every now and again (1 deg lat?).  You can get
> round this in the UK by specifing --useUKgrid at the construct stage
> (might not propogate from the client and server tools) which causes the
> textures to be tiled aligned with UK grid lines across the whole UK.
>
> Using --useUKgrid in conjunction with .osgb36 polygon files, it should
> be quite easy to get each piece of photo in exactly the right place.
> It's been a couple of years since I played with this though, so the code
> (and my memory of how to use it) might have been broken by now though.
> Shouldn't be too hard to fix though.  Also, I was on Cygwin at the time
> and using construct manually without the client - server arrangment, so
> I'm not sure if the --useUKgrid option will get passed through with
> them.

If all else fails I'll just write a wrapper script for it so that the
client tools call the wrapper, and the wrapper adds --useUKgrid and calls
the real prog.

I figure if we get these techniques worked out now then when things like
texture paging and LOD are available we'll be able to get the scenery
updated with minimal effort.

-- 
Jon Stockill
[email protected]