Collisions with multiple nodes using the same model

Scripting Issues
1

I have several nodes using the same model. So when a collision occurs with any of them the name in the collision entry is the same.

How do I grab the information that it was “block2” or “block3” that was hit, and not just “block”?

2

just alike any other information

get the collision entry get get its from or to node … see
panda3d.org/apiref.php?page=CollisionEntry

3

Um, yeah, checked that. I didn’t see anything there that looked like it would give me the info I needed. I’ll look again…

Here is what it gives me if I use entry.getIntoNode() or getFromNode()

As you can see the CollisionNode doesn’t say that it is block1 that was hit, just that it hit block.

Well, getNodePath gives me this:

Somewhat helpful, I guess I will just have to figure out how to use that. Unless there is a way to get just “block1” from it…

4

It’s the name of the collision node.
Read for more :
discourse.panda3d.org/viewtopic.php?t=3499

5

You’re looking for the name of an ancestor node. For this you can either write a loop to call getParent() until you find the node you’re looking for, or you can set a tag on the ancestor nodes and call findNetTag() to have Panda do the loop for you (a tiny bit faster than doing it in Python).

David

6

Well, I found one way. I just search the getIntoNodePath for what I am looking for.

    intoHit = colEntry.getIntoNodePath()
    if intoHit.find("block01"): self.blockNode01.detachNode()
    if intoHit.find("block02"): self.blockNode02.detachNode()
    if intoHit.find("block03"): self.blockNode03.detachNode()

Seems to work. But detachNode gets rid of all the block nodes, instead of just the one I am telling it to. Here is the code I use to load the blocks:

    self.blockNode01 = self.playBoard.attachNewNode("block01")
    self.block01 = loader.loadModel("models/block")
    self.block01.reparentTo(self.blockNode01)
    self.block01.setPos(startX+7,startY,startZ)

    self.blockNode02 = self.playBoard.attachNewNode("block02")
    self.block02 = loader.loadModel("models/block")
    self.block02.reparentTo(self.blockNode02)
    self.block02.setPos(self.block01.getX()+7,startY,startZ)

    self.blockNode03 = self.playBoard.attachNewNode("block03")
    self.block03 = loader.loadModel("models/block")
    self.block03.reparentTo(self.blockNode03)
    self.block03.setPos(self.block02.getX()+7,startY,startZ)

So how do I get it just to remove the block that had a collision?

goes off to look at the manual more

Edit: Oh, it’s cause all the if statements return true…

7

So I am trying to do it like you say. I use:

self.blockNode01.setTag("block01","blocks")

to set the tag. And then:

if intoHit.findNetTag("block01"): self.blockNode01.remove()

to check to see what was hit, and remove it.

But it removes all the blocks except the one that was hit. Am I using the tags wrong? I read the documentation on the functions, but it wasn’t very clear…

8

Just to let you know, I solved it. I converted the intoHit from one of the posts above into a string and used that to compare with. :smiley:

9

NodePath.find() and NodePath.findNetTag() both always returns a NodePath, not a bool. And if they fail to find what they’re looking for, they return an empty NodePath, not None. An empty NodePath is still considered a True value by Python, which is why your attempts like:

if foo.find("blah"):

and:

if foo.findNetTag("blah"):

are always going execute the body of the if, regardless of whether the find succeeded or not. You could do something like this instead:

if not foo.find("blah").isEmpty():

David