Sun's visible diameter

[Mariusz Kuźmiński]

Hello, I'm using ver. 1.6.1. I see diameter of Sun the same from Earth and from Sedna, when Sun is visible as a star, not a shield (as attached). Is it a bug or is it correct?

[selden]

You have "Star style: scaled discs" enabled. Bright objects are drawn large.
Type a Ctrl-S once or twice to select "Star style: fuzzy points" or "Star style: points" to see a more appropriate diameter.

[Mariusz Kuźmiński]

OK, thanks, but I prefer "scaled discs"

[ajtribick]

This is a side-effect of trying to represent the huge range of lighting on a computer monitor with limited dynamic range. There's no particularly good resolution to this without rewriting the render engine to handle HDR properly.

[t00fri]

This is a side-effect of trying to represent the huge range of lighting on a computer monitor with limited dynamic range. There's no particularly good resolution to this without rewriting the render engine to handle HDR properly.

Both ChrisL's shader stars and notably my celestia.Sci shader stars are a vast improvement compared to scaled discs etc. ChrisL's stars are to be viewed in his Cosmographia software and are rendered via the vesta@ASTOS engine. All these star renderings handle the large range of star brightness via both a variable OGL point size and a variable Gaussian glare component.

With some know-how in OGL, it's not too hard to also implement such stars into Celestia. Chris' original shader star patch could be a start.

As an example for a successful rendering of a huge range of star brightness in celestia.Sci, here is the dim 10.2m globular NGC 2419 along with "bright" background stars (7.2m, 9.66 m+10.76m and 11.16m ). Many stars in the globular cluster are dimmer than 25m (!!), yet are rendered with the same star shader code as the normal background stars!

[Click on image by all means]

n2419_celSci.jpg

If one zooms deep into those extremely dim NGC 2419 cluster stars, one is once more overwhelmed by star brightness (and subtle colors)

ngc2419_large.jpg

With these shader stars, the size of the sun as viewed from Sedna looks perfectly fine, as you can see here:
[Click on image by all means]

sedna_sun.jpg

Fridger