I'm not totally sure what you are trying to achieve...is the ground always flat? It is flat in the case you are describing (because it's a Box...why don't you use a Plane btw...?), but is this the normal case or just for testing? If your ground is not always flat, i think calcMinDistance() could be worth a try (remember to set collision modes accordingly). Another possibility would be to use a completely different data-structure to store the height of the ground at a specific position (a kind of heightmap). This could be faster than doing all on the polygonal level.
If the ground is always flat, there are two possibilities to get your objects "grounded". The first is: Try different values until is works... :wink:
The second is to obtain the dimensions of the object to do the translation accordingly. The problem is, that jPCT doesn't give you the object's dimensions. I can add this, if it would help (i.e. add the possibility to get the bounding box dimensions, which basically are the objects dimensions).

JAW is not a very common format. In fact it was used by a very basic 3d engine for DOS some years ago and i decided to support it, because it's so simple and easy to understand. I once had a small converter for ASC (or 3DS...i don't remember it correctly) to JAW but i guess that it's gone over the years. I suggest that you use ASC instead.
IE and refreshing applets is kind of a problem. Try to reload the page holding down the STRG-key. This helps sometimes but not always. I usually quit IE too to refresh the applet-content.

To compile it (and to run the compiled file), you need to add jpct.jar (from the libs-dir of the API-distribution) to your CLASSPATH. Depending on the OS you are using the procedure to do this may vary. To add jpct.jar temporally to the CLASSPATH (during compilation only(, something like

javac -classpath %classpath%;[path_to_jpct]\jpct.jar Bounce.java

should work. Anyway, adding it to the CLASSPATH permanently is the better solution IMHO.

Wow, the forum is overcrowded... :wink:
Anyway, jPCT 0.80 has been released. I had to modify some of the collision-methods in Object3D and World to make them returning the ObjectID and not just true/false. This way, it's possible to say that object x collided with object y and not just that x collided with something.
The source of the famous bounce-example (in the API-package) has been slightly modified to reflect this change.
Furthermore, a new Primitive (a box) and a new automated texturing method has been added as well as support for linear distance fog in a very basic form.

...albeit the former forum wasn't used very often, i thought that it might be usefull to have one up and running again. So here it is!