Re: Mercator Projectio - how to do it across dateline...

Hi Lsc,

Lim Siew Cheng wrote:
>
> hi there,
>
> I've been through the openmap applet and played with the mercator
> projection...and would like to know how the tiles appear when an area spans
> across the dateline

We don't have tiles by default. If your layer is managing tiles, then
you have to use the projection object to find out where the tile should
be placed.
 
> In our project, we have mercator projection as well, but I'm having
> difficulities making tiles appearing when I issue a query to see an area
> across the dateline eg ( 160.0 80.0 -160.0 60.0 ) (160W to 160E )
>
> Is there any special "operations" to be done when we want to project those
> tiles in those area?

Do you have any more information about the tiles you are trying to
display? Are you creating OMRaster objects with the tile data?

> (ie . some values in the formula have to be chang3ed etc? )
>
> I've played with the spherical formula, the ellipsoid formular, but all my
> tiles are projected off the screen ( ie I could only see
> -180 to -160.0 the rest are projected right of those (and hence fall
> outside the screen say 1024 x 768)

It's hard to offer more advice without knowing what kind of objects you
are trying to display and how they are constructed. Also, are you sure
that the tiles that are not appearing are being drawn to the right of
the screen, instead of being ignored?

Regards,

Don

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