modelling and animating a satellite in celestia

[Orcun]

hi celestia lovers, I m quite new about the program celestia I heard it from my supervisors, and I m working for the modelling phase of a cubesat, the thing that I have to do is, I have the solidworks model of the satellite and also the pictures in jpeg, I have to madel and animate this satellite around earth and record this animation maybe with camtasia, how I can animate this jpegs as a model in celestia?

and I have one more question, I installed celestia from its web site it was all in english and I didnt choose any language, when I open celestia now it works with german, maybe the reason I have a german windows but how can I change it to english?

[Orcun]

any help? come on it shouldn?t be that hard, I m sure somebody knows how to do it, I have to deliver this animation this week please help

[selden]

Unfortunately, learning how to do all that you want in less than a week probably is not realistic.

If you haven't already, please read the Users Guide at
http://celestiamotherlode.net/catalog/d ... ation.html
and the manual at
http://en.wikibooks.org/wiki/Celestia

Celestia can make its own movies. You don't need to use camtasia.

You'll need a 3DS export module for Solidworks.

3DS models can be animated within Celestia by defining the moving components as separate objects with their own orbits and rotations relative to each other.

The Windows language locale can be changed in the "Regional Settings" of the Control panel, or you can force Celestia to use English for everything by deleting or renaming the folder Celestia/locale

[Orcun]

thanks for help selden, but fortunately learning quite much thing took less than one day, today I managed to put my model into celestia by converting solidworks model to 3ds and modifying a ssc file from another satellite file.

Now there is just one problem above all, when I convert my model into 3ds format the colors of model are gone and it only looks like a metal bunch cube! I have to add some textures but I dont know how you define them to celestia, I saw some other satellite files they just put them into textures folders and all is done! at leats I want to define 8 solarpanels on my satellite, I have the jpg?s of solarpanels how can I implement them on my model in celestia?

[selden]

If Solidworks is correctly exporting the 3DS files, then you should only need to put the surface texture files in \textures\medres in the folder where you have defined your cubesat Addon.

You may need to scale the textures so they are a power of two on a side: 512x1024 for example.
The size of textures used on a 3DS model is limited by your graphics hardware. 1024 is common for older cards. Newer cards can use textures as large as 2048x2048 or 4096x4096.

[danielj]

Actually a Geforce 8 or above can use textures up to 8192X8192.

If Solidworks is correctly exporting the 3DS files, then you should only need to put the surface texture files in \textures\medres in the folder where you have defined your cubesat Addon.

You may need to scale the textures so they are a power of two on a side: 512x1024 for example.
The size of textures used on a 3DS model is limited by your graphics hardware. 1024 is common for older cards. Newer cards can use textures as large as 2048x2048 or 4096x4096.

[Orcun]

I installed solidworks exporter, and exported the model to 3ds but when its exported all the textures are gone:S anyway I installed 3ds max and imported the model that i export from solidworks in it and textured again, exported the textured model to 3ds again and put it inside celestia?s model folder and used the .bmp from textures folder in celestia while I m retexturing in 3ds max, but at the and it doesnt work! I tried to open the file that I exported from 3ds max in 3ds max and the textures fail! it says the coordinates of textures are lost! so it just shows basic color of bmp file when I run celestia:? what is the problem how can I solve?

by the way my graphic card is ATI Radeon HD 3200 graphics
the size of the picture is 1837x1837 bmp file

[selden]

Sorry, I can't help with the problems you're having with your modeling programs' import and export functions. Maybe someone else here can, but you should ask those questions on forums associated with those products.

However, I strongly recommend that you be much more conservative with the textures to be used with Celestia:

1. resize the 1837x1837 image file to be 1024x1024
3D models can use any size of image file, but the display hardware is much more limited. You don't have to change the image size specified in the modelling software. Realtime 3D has much more stringent constraints than non-realtime.
Most graphics cards require power-of-two texture image sizes.

2. convert the BMP file to PNG, JPG or DDS, whichever is supported by your 3D modelling software. Celestia officially does not support BMP. Only a small subset of BMP is implemented and if it works, you have to consider yourself lucky.

[Orcun]

then how these tributters creating textured models in 3ds format while its not possible to export them properly from 3ds max wtih textures? there are so many released .3ds models with textures here http://www.celestiamotherlode.net/

[selden]

Very few people involved with Celestia use 3DS Max for modelling.: it's extremely expensive. Most use free or inexpensive modellers. Their exports of the 3ds format tend to be relatively reliable. My impression is that AutoDesk is doing their best to deprecate the 3ds format. It lacks many of the features required by modern animation software.

You might want to investigate 3rd party 3D format conversion software. For example, Right Hemisphere's 3D conversion product Deep Exploration has good reviews and has a free trial period.
http://www.righthemisphere.com/products ... e_cad.html

[Orcun]

thanks selden for your help, but I have to leave the office now, for 10 hours still no results for texturing, tomorrow I will try to do with the program that you indicate in the link, and write back the result here

[ziggy]

aint so easy then.Is it up yet? Have I got that right that any movement in Celestia has to be in terms of orbits?and is there not an easier way.

[rthorvald]

Now there is just one problem above all, when I convert my model into 3ds format the colors of model are gone and it only looks like a metal bunch cube! I have to add some textures but I dont know how you define them to celestia, I saw some other satellite files they just put them into textures folders and all is done!

There are two possible explanations. The first one is least likely: if there is a texture declaration for your satellite in the SSC file, it will override any texture mapping in the 3ds model.

The most likely explanation is this:
Celestia can only undertand 1 texture to 1 mesh.

To explain: if more than one texture is mapped to a particular mesh in your model, the texture mapping breaks in Celestia. This means you need to open your model file and re-map all the textures in the cases where more than one is mapped to a single mesh. This means that if you have such an instance, you will need to cut the mesh in question along its textures, then re-map each texture to each new part after the cut.

Alternately, if the mapping is very simple, you can try to combine all your jpgs to a single texture map and put it in the SSC declaration. But in most cases, that would be almost impossible to get right.

- rthorvald

[bh]

You could try importing the model into Anim8tor and apply the textures to the mesh there. Sorry I can't be more help... good luck. I'm looking forward to some screen renders.

[selden]

The texture mapping limitation (one texture per 3DS mesh) is in Celestia's interpretation of 3DS meshes. (It could be a limitation in the design of the 3DS format itself, I'm not sure.)

Celestia's CMOD models have no such limitation. Anim8or allows you to apply a separate texture to each face of a mesh. A CMOD export script is available for Anim8or which preserves the individual face maps. For more information, see http://www.lepp.cornell.edu/~seb/celest ... lling.html

[selden]

aint so easy then.Is it up yet? Have I got that right that any movement in Celestia has to be in terms of orbits?and is there not an easier way.

An EllipticalOrbit or an xyz trajectory or a ScriptedOrbit can be used to specify an object's motion. To use the latter, you have to write a Lua function which returns xyz coordinates.

The documentation for SSC files describes these different techniques.

See http://celestiamotherlode.net/catalog/d ... ation.html and http://en.wikibooks.org/wiki/Celestia