New version of AutoStar for FSX released

[cwright]

Hello all,
I've just released a new version of AutoStar for FSX. You can get it here:
http://www.kline.demon.co.uk/AutoStarX.zip

AutoStar adds to the night sky in a number of ways, for example displaying the brighter planets in the correct position according to the date. It can also add comets, images and celestial circles.

New features:
1. The brightness of the planets changes as a function of phase angle and distance from the Earth.
2. The SAO star catalogue can be imported, thus allowing many more stars to be displayed.
3. The appearance of the background stars can be adjusted: brightness, dynamic range and colour strength.
4. Brighter stars are automatically displayed as small groups of up to sixteen stars, thus increasing the effective brightness dynamic range by a factor of sixteen.

The SAO star catalogue has about a quarter of a million stars going down to magnitude 9 (far fainter than can be seen by the naked eye). The import function allows you to set a limiting magnitude, so you can set the number of displayed stars.

In this version you can change the appearance of the background stars, for example by changing the brightness or increasing the star colours. With a high colour and brightness setting the sky will look like a huge Christmas tree!

Some screen shots:

Comet west


Happy Christmas!


A comet, some planets - and Pluto!


Exaggerated star colours and brightness


Celestial circles with coordinates let you navigate across the sky (circles don't show in this shot)


Have fun and Happy Christmas!

Best regards,
Chris

[loomex]

Looks great, however, the first question EVERY one is going to ask: WHAT ABOUT MY PRESCIOUS FRAME RATES? As you know this is a big issue.
Any insght for us?

[cwright]

Looks great, however, the first question EVERY one is going to ask: WHAT ABOUT MY PRESCIOUS FRAME RATES? As you know this is a big issue.
Any insght for us?

I don't have any figures but the impact is generally small. If you're just adding the planets it's essentially zero. Images and comets add many more stars but the impact is still quite small. Of course, by carefully optimizing any bitmap images you can greatly reduce the number of extra stars and still get good results.

If I can do some measurements I'll let you know....

Best regards,
 Chris

[cwright]

Hi loomex,
 I did some tests on the Comet west bitmap. It's a relatively large bitmap. AutoStar works by converting every pixel (except black pixels) to a star. Therefore if you're not careful a large bitmap will create a large number of stars and frame rates will fall.

You can help frame rates in two ways. First, when creating or editing a bitmap, ensure that all dark/non-displayed pixels are black (RGB values 0,0,0). Black pixels are not converted to stars.

Second, there is a minimum brightness setting. For example, if you set it to 10 then pixels with average brightness of 10 or less will not create stars (a pixel of brightness 10 would probably be invisible, anyway).

In my test, without the comet the frame rate was 20 FPS.

With a minimum brightness setting of 5, 81000 stars were created and the frame rate was in the range 12 - 15 FPS, so there was a significant impact. A large proportion of the created stars was so dark as to be invisible.

With a minimum brightness setting of 20, 16000 stars were created and the frame rate was around 18, so there was only a small impact. The comet still looked essentially the same.

With a comet and a number of user objects plotted (e.g. a lunar eclipse and some Messier objects) well over a hundred thousand stars can be created (the manual recommends you don't exceed 150,000!) If there are a number of user objects the impact may be small because only a fraction will be in view at any time. In all my testing I've never noticed a frame rate fall that was serious enough to affect the overall experience.

I hope this helps.

Best regards,
  Chris