Re: [Plib-users] It's Possible???

[Steve B. <sjb...@ai...>]

Horacio Sanson wrote:

> I want to have two 3d objects to be defined separately and in some point make
> them part of the same object, so any transformation affects both objects
> equally. Is this possible???

Yes.

You need to visualise the SSG scene graph as a tree:


                         parent node
                             |
              _______________|_______________________ _ _ _ _ _ _ _
             |                               |                     |
   Player_ssgTransform              Sword_ssgTransform     Rooms,Dragons,etc
             |                               |
     ________|________                       |
    |                 |                Sword_ssgBranch
 Body_ssgBranch   Arm_ssgTransform           |
    |                 |                      |
 Body_ssgLeaf(s)  Arm_ssgBranch        Swort_ssgLeaf(s)
                      |
                  Arm_ssgLeafs


When the player picks up the sword you should probably do the following:

   add the Sword's ssgTransform node to the Arm's ssgBranch

   removeKid the Sword's ssgTransform from the parent node

   change the Sword's transformation to position it in the player's
   hand relative to his arm.

>From then on, the sword will stay 'glued' to the player's hand.

The scene graph should now look like this:

                         parent node
                             |
              _______________|_______________________ _ _ _ _ _ _ _
             |                                                     |
   Player_ssgTransform                                    Rooms,Dragons,etc
             |
     ________|________
    |                 |
 Body_ssgBranch   Arm_ssgTransform
    |                 |
 Body_ssgLeaf(s)  Arm_ssgBranch
                      |______________________
                      |                      |
                  Arm_ssgLeafs               |
                                     Sword_ssgTransform
                                             |
                                             |
                                      Sword_ssgBranch
                                             |
                                             |
                                     Swort_ssgLeaf(s)

Make sure you add the sword to the player *before* you detach it
from the parent node because SSG deletes nodes that are no longer
connected into the scene anywhere.
  
In general, you could use this to place the sword onto moving
vehicles, to make the player ride a horse, etc, etc.

-- 
Steve Baker                  http://web2.airmail.net/sjbaker1
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