get into point channels

[Juzwa]

Hi, 

I want to have more control in my setup and I've been trying many things. But the further I go I can see that the best thing would be just to be able to get some control from the actual points.

So for example I have 2 points. They have some positions, velocities and additional channels.

Then I want to reuse some o those channels to steer my sim in DOPs, eg. use vel to control velocity.

So the esies way I see it is just to get their channels with expression, no SOPs. but how can I get into the specific point channels? This is what I mean:

point[0].pos.y

len.point[0].vel

ofcourse this is a made up code, im not very familiar in vex. but you get the idea

P.S. And when I finally get each points channels, can I use them in DOPs? For example:

Each point have different velocity. So inherit diferent velocity for each point emitter

Edited June 28, 2016 by Juzwa

[fencer]

in popnet sim inherits incoming velocity

[Juzwa]

Ok sorry I'm not expressing my issue the right way. So this is what I got:

Two points, point A [0,0,0] and point B[0, animated y, 0]. Thanks to animated P.y of point B I can calculate the velocity vector, which is just P.y. And now I want in DOPs to make emission but only from point A using the vel on B.

So the only thing I need is just to transfer vel atrib from point B to point A, and delete B. Easy.

And I'm guessing this is just oneline of code in vex. I'm trying to figure it out in Attribute Wrangle with this: int test = pointattrib(0, "P.y", 1, 0);   but it errors out

In help it says: type pointattrib(int opinput, string attribute_name, int pointnumber, int &success)

success: Set to 1 if the import was successful, 0 if it failed due to no matching attribute or invalid number.

So I dont get this success at all. I mean how do I set it to success or fail on import? Its like asking wheather you want the expression to evaluate or not

I have also tried point(0, "P.y", 0); and it works, but does not return anything else than 0. Which means it fails on import. And it does not make sense why

Edited June 28, 2016 by Juzwa

[Toledor]

Hi Juzwa.

 

I'm not sure if i understood your doubt. I attach a hip file that does the following:

- Two points, one of them is moving, the other is still.

- I transfer speed from the moving pt to the still one using point expression in point wrangle.

- Then, in a popnet, still point emits particles based on moving point's speed.

I hope that's useful. Sorry if it's not what you needed! =D

emitPtBspeed.hiplc

[Juzwa]

Thx for the file  This is kind of close to what I was looking for. 

Actually it's my fault, I cannot express my issues sometimes. Especially since you can do the same thing in Houdini in many different ways. Sometimes I tend to loop myself over one singe way  

I fixed the issue with this expression:

vector test = point(0,"P",1);
@v.y = test.y;