Zezo forum:

Post by Ricardo | 2009-06-08 | 03:12:59

Hi everybody !
I recently adopted the Sailing Simulator on Leg 8 !

But could anybody tell me why angle measures with MBRuler dont fit with Directions give by SS on routes ?

Is it possible to test other routes, with passage point of my decision ?

Thanks for the help ...

R.

9 Comments

Post by Vigilante | 2009-06-08 | 06:31:04

I gave up on MBRuler a long time ago. It's useful, but not an expeditious use of your VORG time!

Post by Ricardo | 2009-06-08 | 09:33:16

OK... but what about angle measurement ?????
Thanks

Post by Vigilante | 2009-06-08 | 10:12:24

The MBRuler strikes me as very accurate.

Post by MMB | 2009-06-08 | 12:42:16

I think MBruler don't use the drift due to the force and direction of the wind versus the boat...
MBruler is an accurate angle measurement.

;o)

Post by zezo | 2009-06-08 | 13:29:37

The problem with measuring angles on screen is the map projection, used in the game and the site.

It's not conformal - the angles do not match, unless you are at the equator. In fact it's not real projection, just linear mapping of (lat,lon) to (x,y).

The problem with the game is that now the boat outline does not point in the real direction when you steer and you risk hitting an island or something.

With the site it's only cosmetic issue - sometimes tacks and jibes seem to be with less than 90 degree difference which is unnatural, but you can always check the numeric data.

And you can set destination (and origin) points via the right mouse button or by control/alt click.

Post by Vigilante | 2009-06-08 | 17:27:04

Yes!

"The problem with the game is that now the boat outline does not point in the real direction when you steer and you risk hitting an island or something."

I noticed that more pronounced lately. Initially, I thought the game had some how <i>slipped</i>. Then it occurred to me it's our northern latitude!

Post by RodH | 2010-03-08 | 20:58:53

2nd word, 3rd line:--'can' , rather than 'cannot'. I'm not the best typist in the world....

Post by RodH | 2010-03-08 | 23:52:28

I don't think that 'edit' is working right...it wiped out my post...???
I was trying to promote the idea of a spherical map projection in which the viewpoint is directly above the map centre at all times, just like Google Earth. This would eliminate all problems of rhum lines, great circles, incorrect distances and crazy angles.
While spherical charts (small pieces of the surface of a globe) would be impossible to store and be difficult to use with straight rulers, this is easy to do on a computer. Mercator would need to get himself another Job!!!

Post by zezo | 2010-03-09 | 00:57:04

It's hard to do it in web browser. Google earth uses heavy client-side rendering (utilizing your latest opengl capable video card).

Even google maps uses some simplified projection.

It's not entirely impossible to do server-side but the amount of traffic needed may not be practical.

It does not really matter for this site, but the game itself could use some better projection or just get rid of the red dots and plot a real track. But this has been discussed hundreds of times and the guys just don't care.