# My question about Blueprint FInterpto...?

Hi ;

In Event Graph , by pressing “spacebar”, I would like to interpolate between value “A” to “B” , smoothly :

&stc=1

Unfortunately , It doesn’t interpolate and just jumps from A to B.

Thanks for helping.
MSD.

Are you completely sure it’s instantly jumping from 0 to 1?

The way you have it set up, it’s going to go up by 0.2 every frame, which would likely be somewhere around 1/60 of a second in my experience.

Try printing out the values each tick and see if you get:

Spacebar pressed
1
0.8
0.6
0.4
0.2
0
0
0

I think it may be working, just happening really fast.

You want to set your target to 0 or 1. Your Current value should come from whatever you are setting in your return value. For instance:

You have float X.
X = 0
You press your space bar and now X should move toward 1.
Get the value of X and plug it into your current
Target is now 1
Based on Delta Time and Interp Speed your return value will = X+((1-X)dTInterpSpeed )(I think that is the math, I’d have to look at the source). So if Current =0, dT is .05 and interpSpeed is 2, and target is 1.

X=.1
X=.19
X=.271
etc.

This is why interpTo starts fast and slows towards the target. If you want a constant speed from current to target you can use the interpToConstant node.

Hi Predatoria ; To check what you said, I don’t know how could I printing out the values each tick …

Hi James94Hodges ; I want to set my target from 1 to zero. and I changed my node to interpToConstant, but I get same result.

What James94Hodges is referring to is the “Current” input you have.

The interp node needs to be called each tick / each frame. And “current” needs the current value of whatever you want to interpolate. It can not be a static number. The target can be whatever you desire. But “current” **needs **to be the current value. And you have to store the result in the variable that feeds current so you have continuous updates. And not a similar number all the time. Because you come from a static number and want to a static number.

Hi** Erasio ; **I got it and now it works , thanks everyone.