[BUG] BP - float property track in matinee

I’ve set up a simple blueprint that enables me to control the strength of a spotlight and an emissive value of a material at the same time via the float property “light intensity” on a skeletal actor (imagine a flashlight mounted to the chest of a character). It works fine in editor, but when I add the property in matinee and key it’s value, then although I can see the value rising when selecting the actor and scrubbing through the timeline, the result (more spotlight brightness and glow of the material) doesn’t show up/doesn’t get updated. But let’s say I’m in the middle of the timeline and the “light intensity” has a value of 2.5, if I now type in the value of 2.5 again manually, the result kicks in but still doesn’t update when I scrub through the timeline in matinee again.

Hi Christian,

I am attempting to reproduce this issue, but having some issues. I do not think Could you provide for me a screenshot of your matinee and BP setup? Any additional details would help me to reproduce the error.

Thank you,

Alexander

Here are some screens, hope it’s better understandable now.

Thank you for this additional information. It looks like you need to make sure to set your material. Let me know if that changes anything before we move ahead with other solutions. Also, you may find it easier to do a Timeline within the Blueprint as opposed to using the matinee.

Thank you,

Alexander

I can’t access your link.

I apologize. I have changed the link and it should be working for you now. Please let me know if it does not work.

I set the material, but still the same issue.

Could you please provide a screenshot of the updated blueprint? I am going to bring a specialist in on this and he will want to see the blueprint in its current state.

Of course:

Hi Christian,

So I have been told that you will need to make sure to update your set brightness and scalar parameter on a tick event in the eventgraph. It is currently only being set on construction.

Also, we would like to take a look at your level BP to see how it is using the Light Intensity float and passing it along to the BP.

Thank you for your cooperation during this investigation.

I have a problem with the tick event:
Since it’s a skeletelmesh BP, it says it can never tick. As for the level BP, I only use it for starting the matinee sequence, nothing else.

Could you please try reparenting your Blueprint to the Actor class and try that? You will have to bring your skeletal mesh back in. If that does not work, then the best solution may be to create a new Actor blueprint. That will allow you to use OnTick.

I got it to work by using an actor class, the eventgraph and a tick event at the beginning. Now I can control the lights in matinee BUT using an actor class has two downsides for me: The missing anim control track in matinee. And I attached a camera to a bone, which I also can’t do with an actor class. I know I could add a camera component in the BP but I want to be able to control it’s postprocess properties in matinee so that’s not an option either. I think I’ll scrap the idea of using a BP for this character, for now.

If you are attaching a camera to a bone, then you should use a pawn or character class. You can then do an attachment set up in the construction script like so:

Pawn and Character classes allow you to call socket information in your blueprint. Please let me know if this has resolved the issue.

I really appreciate your effort, but I’m already at a point where I can’t change him into a BP character or make other fundamental changes, so I have to leave it at that as far as BP goes. Again thanks for your time and effort on this!