"Kasparian, Raffi J." wrote:
> Shawn,
>
> 1)Maybe I'm misunderstanding your request but I don't think it is necessary
> to use Node.getParent() in order to be able to attach and reattach one
> subgraph to another. By using Group.moveTo() and BranchGroup.detach() my
> program attaches the view platform to whatever live BranchGroup I need. Have
> you tried this?
It is true that I do not need getParent() to attach or detach, but I do need it
to find the node I want to attach and detach from...
> 2)In order to calculate a local to local transform, you can use
> Node.getLocalToVWorld on Node A to get Transform TA, Node B to get Transform
> TB and then by doing something like multiplying TB by the inverse of TA you
> get a local to local transform. I'm pretty sure that I've done this in my
> program but I'm being vague here because my Matrix math is not very solid
> yet.
Again, as I wrote before, I can use LocalToVWorld to compute the transform for
me. But I have nodes in the scene graph that are derived from the regular
Java3D scene graph nodes (a' la our OpenFLT loader) and there is additional
information in those nodes that I need to compute what I really want. In one
case that is the total linear and angular velocity of a chain of transforms,
i.e. the rate of change. When doing attach and detach for live world, detach
speed is very important for realistic effects. For example, if I am on a
moving platform, and I jump off, I need to take into account my launch motion
AND the composite motion I had from being on the moving platform, so when I go
into world coords, I am moving correctly, not just positioned correctly.
Therefore I need to "walk the tree" to get that information.
--
__________________________________________________________
Shawn Kendall Full Sail Real World Education
Course Director 3300 University BLVD
Real Time 3D for Gaming Winter Park FL 32792
[EMAIL PROTECTED] http://www.fullsail.com
__________________________________________________________
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