Modelling

Modelling basics

The community currently uses a wide range of modelling programs, from Blender to Lightwave to 3D Studio Max and others. Converters to the .POF format, as used by Freespace 2 is available via a plug in for 3D Studio Max or via the Pof Construction Suite program for .cob (Truespace) files. Any models to be made need to be converted to one of these two formats.

Limits and Guidelines for Model Making

SCP Team Recommendations

The new HT&L (Hardware Transform and Lighting) feature of FreeSpace 2 SCP has allowed a vast increase in the number of polygons that can be displayed at any one time, however, in order to keep gameplay smooth, the SCP team recommends the following rules when making models for use in FreeSpace 2.

Textures :

1) Use as few textures per model as is possible, optimization is the key, for fighters and bombers you should only need a single 512 x 512 map for the model. Capital ships can use more textures, but the less textures and the less memory they take up, the better.

2) Unless it is absolutely vital, use the .DDS format for storing your images. These format files are compressed and are automatically decompressed by your video hardware, so they take up far less memory, thus improving performance. FreeSpace 2 also supports .TGA format files, but these should only be used where .DDS files are causing noticeable compression errors on your texture (this can happen most noticeably with semi-transparent textures). Even then, it is better to use the DDS file format than TGA - just without the DXT compression features, saving them as either uncompressed u888 or u8888 files, latter only if you need alpha channel in the file, which is the case with shinemaps and glass diffuse maps. Even though the filesizes of uncompressed DDS files are usually drastically larger than RLE compressed targa files, they will actually have slightly better performance since both require same amount of video memory (excluding the mip map memory requirements of DDS files), but the GPU's can use the DDS file directly while TGA file needs to be uncompressed before caching to video memory, which consumes processor cycles and system memory. In addition, uncompressed DDS files have the same mip mapping capabilities as compressed DDS files, which targa files don't have.

3) For highly detailed ships, it is better, from a memory point of view, to use one large texture than several smaller ones.

4) Always use texture sizes that are a power of 2, i.e. 256, 512, 1024 or, at most, 4096. However, remember that older ATI cards can only use 2048² maps, thus it is recommended to use this as maximum. You can have different ratios, such as 512x256, but always use these sizes.

Models :

Remember that any Level of Detail models are going to be stored in memory, so use them sensibly. Freespace SCP now uses Mipmap technology, so you no longer need to create LODs for the textures, an old requirement of FreeSpace 2 modding. Whilst polygon count does not have as dramatic effect on performance as texture size does, it is, as always, best to optimize where possible.

Polygon Counts

Whilst there is no fixed limit to the number of polygons you can use on a model, and opinions vary from person to person, the writer finds the following approximate Polygon counts a good guide to work by.

Fighters/Bombers - Less than 6000 Polygons

Cruisers/Freighters - 6000-12000 Polygons

Corvettes - 14000-18000 Polygons

Destroyers - 20000-24000 Polygons

Juggernauts - 24000 Polygons upwards

Though this list should not, by any means, be used as a rule, different modders work to different guidelines.

Note that Detail box models should not be counted directly to the overall number of polygons.

Sub-Objects

The first thing that needs to be understood about FreeSpace models is the hierarchy they need to be placed in to make sure that conversion is a success. Each FreeSpace model is made up of several submodels (which can also use more than one material each) or groups. How these groups are arranged will directly affect how the final model works in-game. Don't panic, it's not as scary as it sounds.

The most important parts of your ship you need to make sure are at least one individual sub-objects are :

Main Hull	The main 'Body' of the ship, will only explode when the ship is destroyed.
Turrets	Any static or rotating turrets, rotating turrets need 2 sub-models. Different sub-object for each turret, e.g. Turret01, Turret02 etc. In the case of rotating turrets, I use Turret01-base and Turret01-arm etc.
Subsystems	Destroyable sub-objects or any other eye-candy. These have the widest range of uses and feature in more advanced features. Different sub-object for each sub-system e.g. Radar01, Reactor01 etc.
Debris	The wreckage of the ship released after it is destroyed. Different sub-object for each item of Debris, e.g. Debris01, Debris02 etc.
LODS	The Level Of Detail models for the main Hull and for so-desired Turrets and/or Subsystems.

Some sub-models can be further enhanced using the SCP ships.tbl expansions such as Animation Code. Always bear in mind what you want your ship to do whilst you are modelling it.

In addition the the LODs, it is possible to add further detail models to you ship using the Detail box feature.

Update ongoing by Flipside