runtime evaluation with bifrost

[batarg]

my goal is to recreate autorotate evaluation in bifrost like i made it with expressions.

expression example:

given:

locator1 - driver

locator2 - driven

locator1 has custom created double3 attribute that stores position

// get previous position
vector $a = <<
	locator1.lastPosX,
	locator1.lastPosY,
	locator1.lastPosZ
>>;

// get cur position
vector $b = <<
	locator1.translateX,
	locator1.translateY,
	locator1.translateZ
>>;
// delta (direction)
vector $dir = $b - $a;

// apply new position
locator2.translateX = $dir.x;
locator2.translateY = $dir.y;
locator2.translateZ = $dir.z;

// store new position
locator1.lastPosX = $cur_pos.x;
locator1.lastPosY = $cur_pos.y;
locator1.lastPosZ = $cur_pos.z;

what it does - its updating driven object while you drag driver

how to recreate this in bifrist graph editor?

[Roland.Reyer]

I believe what you're trying to do is this:

Use "port feedback" to store the last position for the next iteration.

If you RMB on a port of the output you can choose a "port feedback" on the input to connect it to.

In this example (inside a simple compound) "position" goes into "last_position1".

In the next iteration this "last_position1" will show up on the input "last_position" and you can use it e.g. in the subtraction.

[batarg]

wow! i will try it as soon as possible thank you very much!