Thinking Particles, Local and Global Space

[typografschaft]

I don't have cinema in front of me, do you mind posting a screenshot?

[Darter]

You build the particle's matrix using its position and velocity.

Global_Local_Test_Working.zip (http://bit.ly/LGSHoo)

[simonfarussell]

Darter: That's great. Thank you very much, I've been struggling with this for a while. I see now that I didn't need to translate back using the MatrixMulVector. I was probably just neutralising any results I would have got!

Typografschaft: Here's a couple of screen shots. He's my attempt https://dl.dropbox.com/u/1830495/Fail.jpg and here's Darter's solution https://dl.dropbox.com/u/1830495/Win.jpg

[fuat]

You build the particle's matrix using its position and velocity.


i don´t want to hijack your thread, and your setupworks fine, Darter, but only a little correction:
you can get the matrix directly out of the alignment - so there´s no need for the velocity (take the output of the position instead of the velocity, and you will see no difference).
basically you can get your particle´s matrix out of the position, too, since the velocity is nothing else than the derivative of the position (and with this you will even have two nodes less in your setup by the way ;).
the Vector2Matrix node does nothing else than setting the 3 basisvectors defined by the position (with a adjustable direction function).

but still, nice workaround. just wanted to share some information...
cheers
fuat

[Srek]

Alignment and Velocity aren't interchangable. For one, a particle can move in a totally different direction that where it points to. Secondly, the velocity vector does not give you a full matrix, one axis is undefined.

[Darter]

This setup (http://bit.ly/KHq9t6) demonstrates the relationship between a particle's position and velocity.

[fuat]

This is very kind of you, David.
Highly appreciated.