Bounding shapes


There's nothing more horrible than bounding shapes, which don't fit to the car. :-) So I recommend that you spend some time making bounding shapes. I'll give you some tips. Some 'rules' first:

No concave shapes No concave shapes

It won't crash, but these will be straightened out by the game, so you'll lose some of the points you have defined. The workaround for this is to use more than one shape, e.g. having the body in one and the roof in another. (= 2 bounding shapes)
No slanted bottoms between wheels No slanted shapes between the wheels

The whole bottom part between the wheels must not be slanted, otherwise you will get the 'Wheels outside all shapes'-error. It's OK outside the wheels though.
32 vertices maximum per shape / 4+ shapes cause splitting crashes - 32 vertices maximum per 1 shape
- 4+ shapes causes splitting crashes


Although it's rare to have 32 vertices in one bounding shape if you do them correctly, I'll point out that it causes a crash... didn't test it myself, but Cesm told me first. Also, having 4 or more bounding shapes in a car causes a crash if the car happens to get splitted. And maybe in another occasions too... generally, having lot of bounding shapes causes trouble in high-speed collisions. The splitting isn't always too common, especially not with extremely tough cars, but still, try to avoid too many shapes.
An easy way to create bounding shapes with CarEd and Plaything 2:
Creating bounding shapes I 1. Open the actual car in background in CarEd to be able to create the bounding shape meshes. Create the simple 3D-meshes (I've renamed them as BBody and BRoof), creating the vertices clockwise in the left-window. After that you can delete the actual car parts because they are unneeded now, so that the simple components are left. Choose [File/Export .ASC] to export an ASC-file containing these 2 (or more) simple meshes. If CarEd won't create an ASC-file (has happened to me sometimes), simply use the [File/Rename model]-command to give it some name, and try exporting again. Save the ASC somewhere, for example to desktop, temporarily. (easy to find) Remember to write the .ASC-ending in the dialog, such as Bounds.ASC.
Creatings bounding shapes II 2. Load the ASC-file in Plaything 2 with [File/Import ASCII-file]. Then select one of the shapes in the hierarchy list, and go to [Objects/Save non-car .txt file as], and save a textfile in the dialog that pops up. Remember to write a 2-digit number in the beginning of the name (01Body, etc), otherwise PT2 won't create anything. Once this is done, do the same for the other simple meshes as well. (select the object, go save a textfile, giving it another 2-digit number and name)

After you've done that, open the textfiles that were created, find the bounding shape lines in both textfiles, and copy those into your car's textfile. Remember to change the 'number of bounding shapes'-value. Example of this below.

Tip: After this is all done, you don't have to delete the ASC-file: notice how the simple meshes are also an excellent base for a simple model. Just throw in some textures (e.g. screenshots of the actual car) and you got yourself a simple model for your car without extra modeling effort.
2                       // Number of 'Bounding shapes' entries.

// Bounding shapes entry #1
polyhedron
14				// Body

-0.18 , 0.055 ,-0.4
-0.18 , 0.1   ,-0.42
-0.18 , 0.17  ,-0.26
-0.18 , 0.2   , 0.36
-0.18 , 0.07  , 0.35
-0.18 , 0.04  , 0.04
-0.18 , 0.04  ,-0.18
 0.18 , 0.055 ,-0.4
 0.18 , 0.1   ,-0.4
 0.18 , 0.17  ,-0.26
 0.18 , 0.2   , 0.36
 0.18 , 0.07  , 0.35
 0.18 , 0.04  , 0.04
 0.18 , 0.04  ,-0.18

// Bounding shapes entry #2
polyhedron
8				// Roof

-0.17 , 0.17 ,-0.22
-0.1  , 0.24 ,-0.07
-0.1  , 0.24 , 0.04
-0.17 , 0.2  , 0.28
 0.17 , 0.17 ,-0.22
 0.1  , 0.24 ,-0.07
 0.1  , 0.24 , 0.04
 0.17 , 0.2  , 0.28
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