Ai Jumping in UE4 Part 02: Smart Nav Links

In this series of videos we are going to create an NPC which can jump onto or over objects in the Unreal Engine 4. We are going to accomplish this by using the Smart Link component of the Unreal’s Nav Link Proxy, we’re doing this so that we don’t have to rewrite or add to any of path-finding code in the Unreal Engine.
In this video we will create the jumping behaviour using the SMART LINKS component.
The project files (4.19) for this tutorial can be downloaded here: drive.google.c...
Stack exchange on calculating parabolic arc and velocity: gamedev.stacke...

[@jackmann1478]

AI don't jump. Using BT MoveTo, NavLink never triggers. Jumps down but not up

[@AntiAnti]

Thanks for a great tutorial. Naviagion system in UE4 isn't well documented.

[@michaelzhang2532]

TLDR SuggestProtileVelocity function may satisfy your needs.

[@PsyCoCinematics]

Still works! Thank-ya!

[@RATSGAME]

Do you know why the wrong actor would fire the EventReceiveSmartLinkReached? I'm having issues where my nav link blueprints are randomly causing a different blueprint to actually call the event than the one that's housing the Smart Link Comp which the AI is actually hitting. If I have A, B, and C links and my AI hits A, it triggers the A blueprint. Then he proceeds to B and triggers the B blueprint. Then he proceeds to C but it triggers the A blueprint. The Agent and Location are, however, correct so if this is also happening to you, your method may not of made it that noticeable. But it would be if you were to try and change a few of your links to have different times for the jump and then make sure each one is firing that with the correct code. My only recourse seems to be a test to see if the destination is too far from the actor calling the Link Reached event and if it's too far, get all of the links and run a test to see which one is closest to the player and fire that one's...but that scares me when there's links that are tight together...it's kind of infuriating tbh...I hope you can help but it was you who got me this far so great tutorial.

[@blakegt.7326]

Hi, but why my AI enemy keeps falling from edge? it does jump, but sometimes it doesnt stop to make that jump, just keeps walking and falls down. Thanks.

[@BlackDragonStudiosLtd]

Hi Rocco FX, are you saying that your character will jump onto the obstacle without issue, but then sometimes it will walk off the other side and sometimes jump off? If you check the characterMovement component of your character blueprint and scroll down to CharacterMovement: Walking there should be a tick box there for "Can Walk Off Ledges", is that enabled? If so your character should have the option to walk or jump off, the behaviour should be random. With "Can Walk Off Ledges" disabled, the character should always have to follow a Smart Nav Link to get down from the obstacle. I hope that helps.

[@andreasmuller9455]

Thx man. In 4.27.1 i had to delete the SimpleLinks to get the Broadcast behaviour working.

[@kenalpha3]

4.27.2. I deleted Simple link points? Smart links stopped showing too. But jump still isnt working. Nothing works. I hate AI in UE4.

[@KaB__1]

Hey mate, thanks a lot for this! Would you know why my AI character will just stop at the Smart link's Relative Start and won't make the jump when 'Smart Link Is Relevant' is enabled? (simple link and smart link have the exact same Left/Start Right/End coordinates)

[@ErebusWolf]

This is by far the best way to get jumping to work for ai. I just watched two other videos that wanted me to use triggers to make the ai jump and not only was it not a valid solution to my problem, but it was also just a brittle solution in general. Thank you so much for demonstrating this method.

[@BlackDragonStudiosLtd]

Hi, thank you I'm glad these have been useful for you!

[@JoshuaLundquist]

Amazing, thanks, but what / where on earth can I find the "AI_Target_BP" like you've got there? I'm in UE5 so maybe the icons have changed, but all I can see in terms of Targets is as an object I put in the level. Curious how you did that.

[@OnyeNacho]

You just saved me a headache of house-to-house close quarters, AI combat for a 2D top down game I am working on, currently in early access. Thank you.

[@JRHudepohl]

Very useful tutorial, I didn't even need to follow the first part and it works well. Thanks.

[@yopiagung8847]

like howw????

[@sam_making_games]

Why did you stop uploading Unreal Tuts these 3 tutorials have helped me alot!

[@haf8l4d3]

Really nice tutorial. I tried this for a longer time because I've never saw this LaunchCharacter method. So I created a complete new CharacterMovement for this type of jumping, which was much more work. The LaunchCharacter method makes it much easier. Thx.

[@jonayne2176]

Nice video man! Super useful. I got my thing working in minutes thanks to you.

[@analysierer9456]

Hi, this is great, but i have one question. It is not working with a duration lower than 2. Than they stand still und "wait". Higher than 2 is not a problem.

[@warnpeace2008]

Thanks! very useful. I used the node "Suggest projectile velocity custom arc" in the end as was getting some weird results. V pleased to get this working and couldn't have figures it out without this vid.

[@litbid]

For some reason my AI doesn't jump. Some searching around, it seems that the MoveTo node might be conflicting with the Launch function.

[@BlackDragonStudiosLtd]

Hi Louis, does the Smart Link Reached Event still trigger when the launch fails?

[@mcslothalot]

I do have the same problem. The character is ignoring the the navlink point and keeps running against the obstacle. And Im pretty sure Ive followed every step from your videos

[@BlackDragonStudiosLtd]

Hi Careyn, again is the Smart Link Reached Event still triggering? If the character is walking straight into the obstacle, then it sounds like it is trying to following the navlink, but perhaps the Launch Character function is failing... can you make sure the the override booleans are set. I would try giving the Launch Character node a ridiculous velocity to see if it is working correctly, if you split the "Launch Velocity" pin and give the Z (Up) axis a silly high value, some like 10 million, then when your character hits the smart link it it should be fired into the skybox and we'll know if this node was the issue. If that works then the problem might be in the calculate velocity function. Hope this helps. PS. Sorry for the late reply.

[@mcslothalot]

Hey thanks for the reply. I gave your tutorial another try. But its still not working as intended. The AI is still running into the obstacle and the Smart Link Reached Event is not being triggered. The character ignores the link. But if I put the AI in a "cage" so that the only option is to use the nav link, then it works. If I open the cage to the side its like the AI takes the shortest path without using the nav links. It takes the correct path but since its not using the nav links for some reason it keeps running into the obstacle. If I close the cage again it works. Its weird.

[@BlackDragonStudiosLtd]

Hi Careyn, sorry this isn't working for you. Would you be able to provide a link to the project so we have have a look at whats going on? If you not comfortable with that then maybe some screen shots of your environment setup, the nav link options and blueprint, and your Ai setup too? It sounds like the path finding is using the links, but the smart link isn't triggering, so I think the issue is somewhere in the smart link. A screen shot of the details panel and the class settings would be useful in trying to figure it out.

[@LeeringDeer]

Wow, this is by far and away the best Unreal AI tutorial I've come across, thx!

[@ThePhanntom]

For some reason my IA doesn't move in the X or Y axis, just Z and cannot reach to me. The Receive Smart Link Reached is triggering according to the blueprint when I play the game

[@BlackDragonStudiosLtd]

Do you have a link to an image/video of your blueprint and the nav link setup in your level?

[@TheRedflash777]

The most advanced and well-explained tutorial I have seen regarding Nav Proxies, thank you very much!

[@itsnotbloodborne1237]

this is quite literally the ONLY tutorial on this. THANK YOU SO MUCH

[@swinny_]

subbed. Amazing tutorial and exactly what I was looking for - THANKYOU!

[@LucidAnimationTV]

All this to simply make the Ai jump? Nice Tutorial tho.

[@eddypost]

muchísimas gracias !!!! (many thanks !!!!)

[@davidfruchtman5234]

Отличное видео с субтитрами молодец

[@minhduongthuong2178]

sorry, i can't download The project files (4.19) anymore. could you reupload

[@BlackDragonStudiosLtd]

Hello Minh, I'm sorry for the delay. The links have been updated now (we changed our online storage): drive.google.com/uc?export=download&id=1tV9ZP8VcoKS1YQLtsZ_6h-C0aSZWGvwZ

[@CheezyI619]

Thanks for the great tutorial!

[@mattwla]

Perfect tutorial, thank you!

[@w47-p1e]

Any way to make nav links at runtime? That would be sweet

[@BlackDragonStudiosLtd]

Well if your navmesh generation was set to dynamic you could probably spawn them in like any other blueprint, however I've yet to try this so I'm not sure it would work.

[@svenrawandreloaded]

how were you able to do this with the move to node? it seems to break the ability to launch the character for me and a few other people by the looks of it

[@BlackDragonStudiosLtd]

Hmm, we'll have a look into this. Things may have changed with newer versions of the engine. If they have we'll post an update here

[@svenrawandreloaded]

@@BlackDragonStudiosLtd dont sweat it, i figured it out a while back.

[@andrewvo403yana]

Hey. Did you manage to solve the issue? My AI character doesn't change XY location after being launched, although Z is working

[@BitchesLoveGoodra]

I have no idea what I missed but my AI's are doing two jumps to use each nav link proxy rather then one jump. First they jump/launch directly upward then when they land they do a second (but correct) jump/launch... I honestly don't know how I managed this lol.

[@BlackDragonStudiosLtd]

Hello mate, can you pass us a few screen shots or video of your blueprints and we'll see if we can figure it out together :)

[@BitchesLoveGoodra]

@@BlackDragonStudiosLtd I think I found the issue. My character uses alot of root motion animations for walking / running / turning so my animbp is set to extract root motion from everything- switching this back to ignore root motion seems to stop this weird behaviour. I guess it doesn't like root motion driven characters. I have to do more testing but this seems like the cause of the issue.

[@BlackDragonStudiosLtd]

Hey @@BitchesLoveGoodra thanks for getting back so quickly. We tend to avoid root motion when working in Unreal tbh, so it's not something we would have spotted, thank you for letting us know.

[@kimochisaiko6442]

Awesome!!!!

[@12345hjkl789hjkl]

Thank you. This is saving time a lot.

[@BlackDragonStudiosLtd]

Anytime, glad to help!

[@davidfruchtman5234]

upside down man

[@landsknecht_voran]

I think, everything in tutorial is too small, and it's hard to see what are you doing

[@dimensionwar5747]

nice voice buddy you sound a bit funky there dude putting on a voice ?