BP Lerp Node blends too quickly with timeline

I’ve run into a weird issue… I’m using a Lerp node (specifically Lerp Rotator and Lerp Transform) in two different setups so that I can move the player into a position or force them to look at a specific point in the world. In both instances, I’m using a timeline to drive the alpha of the Lerp, but for some strange reason, the duration of the timeline seems to be irrelevant. If I set the length of the timeline to 8 seconds, for example, the time it takes to Lerp to the target location is about 1.65 seconds (I used a stopwatch to test) but the timeline doesn’t finish until the 8-second mark as I tested it with a Print String. The only difference with the Lerp Rotator, the alpha blend isn’t quite as fast. It takes about 3 seconds on an 8-second timeline. I’ve never seen an alpha Lerp work this way and have no idea how to fix it.

When you set the length of timeline to 8 seconds did you also move the last keyframe to 8 second mark?

Most likely is caused by how you’re using the lerp node. Check this https://forums.unrealengine.com/development-discussion/blueprint-visual-scripting/1781338-timeline-completing-movement-too-quickly to see if that’s the problem: changing the values of either A or B, while lerping.

If not, show as some code.

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Lol, yes. That would be a rather big oversight, but totally possible. I forgot to post my screen shot like an idiot though. Lol. I’ll have to do it tonight after work. On my phone atm.

You have to save the initial player location to a variable, not the target location. In your screenshot, the A point changes with each tick, whereas it must be constant for the correct result.

I stupidly forgot to upload the screenshot that I took. Apologies. It’s now been added to the original post. Looks like I’m Lerping incorrectly too. Strange, because I followed a tutorial on how to do this setup.

Setting the location as a variable beforehand didn’t make a difference. It still completes the Look At action in half the time and the Move To much faster. The target itself is static in the world and not moving so I was confused why this would make a difference.

EvilCleric’s and Tuerer’s comments are the correct answer. You need to store the value of the player’s location or rotation and the camera’s location and rotation BEFORE Lerping, otherwise the value is changing while the blend happens and it essentially fast forwards everything.

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OMG thanks. I’m stupid. lol Now that you pointed that out, it’s really obvious. Thanks so much, this fixed it for me :slight_smile: