Sun Textures

[shelbydodgeimp]

Hello, I am new here and to celestia.

I actually just found out about the program from a guy I go to school with. So my roommate and I have been spending the last few nights toying with the program, and I must admit its pretty cool.

I dove immediately into the extras/downloads database, and have gotten a general feel for how things work. I have setup vts for earth, mars, moon, mercury etc.

I found a VT for the sun, but it appears to be a constant texture (always on), my computer isnt the fastest (its merely a 2003 mac g4 tower- and yes that means I am in OSX) and I'd like to lower the lag by having the ability to make the sun VT an "alternate surface texture"

I have tried editing the SCC file in the extras folder, like I did with the VTs for earth, mars, moon etc.

The problem I am expierncing is with the location, forinstance the first scc file line of code on the earth VT is:

altsurface "earthVT" "sol/earth" (the last part being the location).

How do I do this for the sun?

I have tried:

altsurface "sunVT" "sol"
altsurface "sunVT" "sun"
altsurface "sunVT "sol/sun"
altsurface "sunVT" ""
altsurface "sunVT "/"
altsurface "sunVT" "milkyway/sun"

None of which seemed to have worked. What am I doing wrong? I assume the rest of my coding is fine because if I replace the location with say, earth- the skin/texture will become in earth's alternate texture listing (obtained by right clicking the planet).

Anyway hoping to learn and contribute.

[selden]

Unfortunately AltSurface declarations don't work for Stars (like the Sun), which are defined in STC catalogs.

They have to be applied to fake planets which are defined to be slightly larger than the star that is being replaced visually.

The SSC might look something like this:

Code: Select all


"fake-sun" "Sol" {
   Radius 0.75e6
   Texture "astar.*"
   Emissive true
   EllipticalOrbit {
       SemiMajorAxis 0
       Period 1e32
   }
}

AltSurface "alt-sun" "Sol/fake-sun" { ... }
}


Adjust Radius and add orientation and rotational parameters to taste...
nearstars.stc includes the latter.

[rthorvald]

I found a VT for the sun, but it appears to be a constant texture (always on), my computer isnt the fastest (its merely a 2003 mac g4 tower- and yes that means I am in OSX) and I'd like to lower the lag by having the ability to make the sun VT an "alternate surface texture"

As Selden wrote, the Sun texture is actually a dummy that is used as a skin on top of Celestia??s default sun. It is this dummy you must define as an altsurface.

However, if the map you are talking about is the "portrait sun" addon (which is the only Sun VT i know of), this will probably cause the sun to look like a gray sphere...

But: that addon comes with low resolution textures, too. So just switch resolution to avoid the lag. If that _still_ does not help, open all the files in the lores folder with an image editor and shrink their dimensions to half. That, of course, you can do with the hires and medres folder, too. Although quality will suffer, you will certainly get better performance.

BTW, i made that addon on a TiBook G4, so your tower G4 should work fine. Assuming noone has released a Sun VT i am unaware of...

- rthorvald