Transparency and Textures

[GregBurch]

1. Is it possible to put a texture on a (partially) transparent mesh element in Orbiter?
2. Is it possible to make a polygon (partially) transparent that is denoted as an MFD in a VC?

If this is possible, I'd really appreciate getting some tips on how to do this, as the test article I've created to experiment with these issues isn't working so far.

 

[Tschachim]

I'm not sure if this helps, but you can put a (partially) transparent texture on a mesh in order to get the mesh rendered (partially) transparent.

Cheers
Tschachim

 

[Schimz]

No problems, it works fine.

The material must be opaque

Don't forget the alpha channel (purple with black -err... or white, can't remember)

Also, it does not affect the object's shadow.

 

[martins]

I believe (although I don't remember for certain) that any mesh groups defining a texture will exclusively use the texture for transparency information, and ignore the transparency information in the group material. You would therefore need to define your graded transparency directly in the texture (e.g. by using a DXT5-encoded texture file).

The DX7 graphics engine would allow more flexibility in defining the transparency (e.g. by mixing the material and texture transparencies), but there is currently no interface to access these features from the addon level. Maybe external graphics clients could exploit additional features in the future, but this would probably also require an extension of the mesh file format (which could then also support things like multi-stage texturing).

 

[Artlav]

It raises an interesting point - different graphic clients will have different but common new features, so some sort of standard ways to use them is needed.
A flexible extension to the msh format, an extension-style graphics functions retrieval oapi*'s, something along the lines.
Any different ideas?

 

[martins]

Going slightly OT here, but I agree that a more versatile mesh format would be good. We should definitely avoid client-specific mesh file formats, i.e. meshes that can be interpreted by only a specific graphics client.

The general philosophy, IMO, should be for the mesh file to describe in a very abstract way how an object should be rendered, and then leave it to the graphics clients how to implement it. The clients should do their best to match the description as closely as possible, but they are free to ignore anything they cannot do.

 

[Urwumpe]

Maybe it would be good to allow special textures at the beginning of each group, which then act as bump or environment map.

 

[Donamy]

like the flags we have now ?

 

[tblaxland]

The DX7 graphics engine would allow more flexibility in defining the transparency (e.g. by mixing the material and texture transparencies), but there is currently no interface to access these features from the addon level.

I haven't used it before but isn't that the purpose of the function:

oapiSetMeshProperty(hMesh, MESHPROPERTY_MODULATEMATALPHA, 1)

?

 

[martins]

Ha, I stand corrected. Orbiter is smarter than I give it credit for .
(Has anybody actually used this feature, and does it work?)

 

[Artlav]

Has anybody actually used this feature, and does it work?

oapiSetMeshProperty does work, but it causes the Sun to disappear when on.
Used in DGIV for heat shield glow and in Orulex for landscape transition blend.

 

[Schimz]

Used in DGIV for heat shield glow and in Orulex for landscape transition blend.

No Matter/Well's CTV for the reentry shield.

Also my Fatty will have plenty of this fx

 

[Schimz]

oapiSetMeshProperty does work, but it causes the Sun to disappear when on.

Work fine with beta, I've got the Sun :speakcool: