Month: August 2020

I’ve just figured out how to setup keyframe animations in Unreal Engine, and thought I’d make a note of it before I forget. I made the animation above a little while ago by “poking around”, but it wasn’t as smooth as I liked it to be. I think I’ve found the missing bits now, so here’s how it works. From what I gather, Unreal Engine calls Keyframe Animations “Cinematics”. They’re a little tricky to setup, because the whole engine is built for so much more, but in principle we need to:

• create a new Level Sequence
• create a Cinematic Camera
• add the camera as a Track to the Sequencer
• create keyframes for/with the camera
• add a Camera Cut Track
• export your animation as a video or image series

I’m going to create a camera animation like in the demo above, but any regular mesh object and Actor can be animated, including lights and their properties, so this process is not limited to cameras. However you need at least one camera to render out the sequence, at least that’s my goal here. The process will be different if you’d like to trigger the sequence from within a game, which is not in the scope of this article.

Let’s see how to do this step by step.

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Following on from my earlier article about referencing a Blueprint from another Blueprint, Unreal Engine has another interesting way for inter-object communication. Sometimes we need to reference more than one object, say when press a button and want several objects to react, all in their own different way. Imagine pressing a button and a light goes off, a particle effect gets triggered and several enemies get spawned. Event Dispatchers can do that, and here’s how we can use them.

In this example I’ll have a Switch object, and a Lamp object. When we press the switch, it’ll send out a message to which the Lamp (and other objects) can react. Each object can implement the function and execute different code. I’ll only show the abstracted Lamp code here for brevity, from which I’m sure you’ll understand the gist.

Sadly the terminology “dispatcher” is a little confusing. At least to me, it suggests that an event is dispatched (i.e. sent), whereas in reality the dispatcher is actually the listener rather than the sender. Hence the dispatcher needs to be setup on the event that needs to react. A real-world dispatch worker doesn’t work that way (thanks code people for confusing us non-coders).

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