incrementing float attribute over time

[ekan de]

Hey all, this is probably a simple question but cant really figure it out.

I have a grid, and a sphere that i am animating over the grid. This transfers a mask attribute with the mask from geometry node.

I would like to take this mask attribute and use it as a trigger for playing alembics.

Using the solver node for comparing and storing the mask attribute so it stays on 1 if the sphere has moved over a point.

I create a attribute named trigger. Say if mask is > 0.5 the trigger attribute is 1.

When trigger attribute is 1 i need to start incrementing another attribute named animation from 0 and upwards over time.

 

How would i write this in vex so i can plug it into the primintrinsics of alembics that i copy on the grid?

Thx!

 

[fex]

Just store the frame when trigger is 1 and then do after the solver something like:  fit(@Frame, @triggerframe, @triggerframe+100, 0,100)

[ekan de]

I am kinda newbie on vex and how to think it thru, how do i store the frame per point? or well, let me put it this way, how do i combine that with the mask from geometry so the frame doesnt go to nothing after the trigger happens?

 

[fex]

Trigger should be created before the solver and set to zero. In the solver triggerr is only set to one if mask is one and trigger zero like:

if(@mask > 0.5 && @trigger == 0){

@trigger=1;

@triggerframe = @Frame;

}

Hope this helps

[Ziyad]

Hi, I've made a quick setup similar to what Felix suggested. Hope it helps

increment_anim_value.hipnc

[ekan de]

Thank you for your suggestions. I still dont get it to work as i want.

Probably me that is thinking about this all wrong.

 

1. is it possible with vex only to increment a number over time? without the solver at all?

2. My thougts are, to have a trigger attribute, when this attribute is over 0 a new attribute say startanimation is starting to count. This attribute needs to start at 0, be a float and count upwards over time. I

3. i can get the startanimation to correspond to the framenumber but this wont make it start from 0.

Sorry for being a pain in the ass but i dont really get the concepts yet.

[ekan de]

I got a solution working now.

i used the solver node and in that a attributewrangle with this code:

//get mask value from previous frame

f@prevmask = pointattrib(1,"mask",@ptnum,0);
if (@mask < @prevmask)
{
//set mask value to mask value from previous frame
@mask = @prevmask;
}

//increment abcframe over time from trigger

@newabcframe = point(1,"newabcframe",@ptnum);
float fps = 25;
if(@mask > 0){
@newabcframe += 1/fps;
}

Then i put another attribute wrangle after the copy to points where i just set the primintrinsics abcframe to the newabcframe.