Models in scc and dsc

[fungun]

I am working on an addon, showing the Badlands from Star Trek Voyager.
The problem is that my 3ds model works very differently when used in a scc file compared to being used in a dsc file.
Exactly why is this?
Is there a way to get the best of both, either through materials or they way it's modeled?
In a scc file it's solid, but the "floor" can hardly be seen.
In a dsc file, the "floor can be seen, but the model is transparent.
Pics below to explain.
thanks
Tim

http://home.mchsi.com/~wilsontc/modelOut.jpg scc file outside
http://home.mchsi.com/~wilsontc/modelIn.jpg scc file inside
http://home.mchsi.com/~wilsontc/nebOut.jpg dsc file outside
http://home.mchsi.com/~wilsontc/nebIn.jpg dsc file inside

[selden]

Unfortunately, without knowing what you want it to look like, it isn't obvious what might be wrong visually with what you've shown us. A screengrab of how it's rendered by your 3D design program might help.

However, you probably aren't aware that models referenced in DSC files are not (yet?) properly depth sorted. Their facets are drawn in the order that they are listed in the mesh. As a result, DSC models only look right when seen from one direction.

A (correct) feature of Celestia is that it only draws surfaces when their surface normals are pointed toward the viewpoint. This might be related to what you see in the SSC model. If a normal points away from the observer, that facet isn't drawn. E.G. if you model a cube with all of its surface normals pointing radially outward from its center, the surface normals of the far sides of the cube (which can't be seen because they're hidden by the near sides) point away from the viewpoint, while the normals of those sides nearest the viewpoint point toward it. The far sides aren't drawn at all by Celestia. They aren't simply obscured by the nearby sides. If you move the viewpoint inside such a model, none of it is drawn because all of the surface normals are pointing away from the viewpoint. So if you're designing an object that the user should be able to go inside and admire, you have to make sure its surfaces have normals pointing both inward and outward.

When the normals of a few facets are wrong, pointing away from the viewpoint when they should be pointing toward the viewpoint, a model looks like it has holes in it where those facets aren't drawn.

Often it isn't obvious in a modelling program how the surface normals are oriented. You have to make an effort to find out. As a result, they're often mis-oriented by mistake. In Anim8or, for example, you have to go into point-edit mode and select all the surfaces. Those facets with normals pointing toward the viewpoint are drawn yellow, while those with normals pointing away from the viewpoint are drawn blue.

Another thing to remember is that Celestia treats alpha channels differently for its built-in spheres (i.e. planets) than it does for models. The alpha channnel defines specularity for planetary surfaces but opacity for models. As a result, an alpha channel value of 0 is transparent on a model but indicates a non-reflective region (e.g. continent) on a planet. An alpha channel value of 1 is opaque on a model, but reflective (e.g. water) on a planet.

[fungun]

The normals and alpha stuff I knew about. Found out about those the hard way
Here are some screen caps of it rendered in anim8or, and while working on it.
My end result would be to have the solidness of the picture taken in the scc file, with the obvious better looking inside shot of the one in the dsc file, but without the transparency.
Confused yet?
Actually the way I made the model-1. I made the top half, made sure the normals were yellow on top 2. Copied it, but made sure the normals were yellow on the bottom. 3. placed top2 inside top1. 4. copied the entire top half, inverted it and aligned it with the original top half.
So now the top and bottom halves are the same with the normals all facing the right way so I don't fly through it without there being a floor or a roof.
But in a scc file the floor looks great while the roof is way to dark to see.
In a dsc file you can see the floor and the roof, but they're transparent.


Thanks
Tim

[selden]

Some sides of an SSC object are dark because they face away from the Sun. (i.e. they are shaded depending on the orientations of their surface vectors relative to the Sun.) You'll need to include emissive materials in your model, or you might try adding
Emissive true
to its ssc definition, making it glow.