Search in
Sort by:

Question Status:

Search help

  • Simple searches use one or more words. Separate the words with spaces (cat dog) to search cat,dog or both. Separate the words with plus signs (cat +dog) to search for items that may contain cat but must contain dog.
  • You can further refine your search on the search results page, where you can search by keywords, author, topic. These can be combined with each other. Examples
    • cat dog --matches anything with cat,dog or both
    • cat +dog --searches for cat +dog where dog is a mandatory term
    • cat -dog -- searches for cat excluding any result containing dog
    • [cats] —will restrict your search to results with topic named "cats"
    • [cats] [dogs] —will restrict your search to results with both topics, "cats", and "dogs"

Office Holiday

Epic Games' offices will be on holiday from June 22nd to July 7th. During this period support will be limited. Our offices will reopen on Monday, July 8th. 

Pawn <-> Ball collision weird overlap behaviour

Hello, i'm having a slight issue with collisions between my character and a physics actor.

I have a ball that uses a sphere component for its physics and collision and i have a character. What i want is that the player and the ball don't bounce on each other but do overlap.

Problem is, when a ball slowly rolls and the character walks over it sometimes the character gets launched away. It looks like the character bounces into the direction the ball is rolling.

But all of the components have Overlap instead of block, so why is the character being moved on collision?

The following are screenshots of the two actors' collision properties, take note that all of the other components have no collision enabled.

Ball (the object type Ball is set to Block): Ball

Character: Character

Does any one have a clue?

Product Version: Not Selected
bp_ball.png (330.8 kB)
bp_character.png (495.5 kB)
more ▼

asked Jun 03 '14 at 07:00 PM in Using UE4

avatar image

48 6 11 13

(comments are locked)
10|2000 characters needed characters left
Viewable by all users

2 answers: sort voted first

Well, i removed all left/right/forward/backward input actions and tried again, no problem, then i did something that caused the editor to crash.

Started the project up again, added the input actions back, no more buggy behavior... Guess this is fixed then!

more ▼

answered Jun 03 '14 at 09:16 PM

avatar image

48 6 11 13

avatar image Ben Halliday STAFF Jun 03 '14 at 09:18 PM

Hey Rens2Sea,

Glad this got resolved... I was just trying to reproduce it without any luck. Still, that's a bizarre problem and I don't know what caused it. If you see this happen again, please reopen this post. Thanks!

avatar image Rens2Sea Jun 06 '14 at 06:06 PM

Just saw it happening again, in 4.2, on the InputActionFire event (left mouse click). This time i managed to stop it by removing the event, compile and save, and then add it back again. (same as last time, but without the crashing in between)


Well, it's fixed for the Fire event, it now triggers the InputActionForward (W key).

Edit 2

I just changed my MoveForward Axis Mapping to another key, and now it doesn't happen again. Changing it back to the W key makes it go wonky again.

The images show my settings and the blueprint alt text alt text

bug2.png (12.3 kB)
bug3.png (342.7 kB)
avatar image Ben Halliday STAFF Jun 06 '14 at 08:42 PM

It looks like you have the W key set to two different mappings; your Axis Mappings has W set MoveForward, and your Action Mappings has W set to Forward. What are you using Forward for, and is there a reason you have W set to both?

avatar image Rens2Sea Jun 06 '14 at 08:52 PM

Forward is for dodging forward, checking if the player has pressed the key twice in rapid succession, while MoveForward is checking if the player holds the key for walking.

avatar image Ben Halliday STAFF Jun 06 '14 at 09:00 PM

You're confusing the blueprint by having the same key mapped to two different inputs. You probably want to do your check for holding the key down vs double-tapping it using the same input node.

I'm going to reproduce what you have here and see if it causes the same problems you've been experiencing, but either way you should probably make sure you don't have the same keys mapped to multiple inputs.

avatar image Rens2Sea Jun 06 '14 at 09:13 PM

Hmm, that could be it. The last hour or so i tried to trace why the InputActionFire Released node gets stuck in an infinite loop (after which the game crashes) when i touch the ball.

Removed those Forward/Backward/Left/Right input action nodes and now it doesn't do that anymore.

However, it now triggers the InputActionFire Pressed node twice in a row.

The fire action is mapped to the left mouse button and nothing else, so it should't be confused about that.

avatar image Ben Halliday STAFF Jun 06 '14 at 09:23 PM

So you don't have the left mouse button mapped to anything other than Fire, correct? I'm guessing your CatchOrBlock uses a different input, right? Would you mind letting me see what your Fire action looks like in your Blueprint? Thanks!

avatar image Rens2Sea Jun 06 '14 at 09:33 PM

That is correct, CatchOrBlock uses the right mouse button.

Here is the Fire action: http://i.imgur.com/j4JG90K.png

avatar image Ben Halliday STAFF Jun 06 '14 at 09:53 PM

Hm, I don't see anything that should cause that. I might need to build this on my end to see if I get the same thing. In the meantime, try closing and reopening the editor just in case the Action Mappings changing so much isn't causing weird behavior.

And just to be sure: the original question you asked involved strange collision behavior. Has that been resolved, or is that still happening? The problem you're having now is only the double-fire?

avatar image Rens2Sea Jun 06 '14 at 09:59 PM

Well, technically it's the same, except in that case the dodge action event (left/right/forward/backwards) got fired instead of the fire action.

I added some breakpoints and i made a composition from where the fire event is being called from (sort of) and added some info: http://i.imgur.com/hPRWVEO.png

I'll try restarting the editor again.

avatar image Rens2Sea Jun 06 '14 at 10:13 PM

Restarted the editor, same thing happens, two fire events when touching the ballspawner's ball.


I guess i could give you the project if that could help.

avatar image Ben Halliday STAFF Jun 06 '14 at 11:57 PM

Hm, I have a setup like yours now and I'm not getting a double-fire. If you step through your Fire process, what happens when you reach the SpawnActor node? Can you see a delay between the two balls being fired? You just said it happens when you're touching the ballspawner's ball... does this mean you need to be standing on that Actor when it happens?

If you feel comfortable zipping your project and putting it up somewhere where I can get to it, I will try again with your project tomorrow morning. Otherwise I'll keep trying to reproduce it with my project.

EDIT: are you in 4.2 now, or is your project still 4.1.1? If in 4.2, was it converted from a 4.1.1 project? When you reopen your project, is your Ball Object Type still in your Project Settings?

avatar image Rens2Sea Jun 07 '14 at 11:26 AM

It happens when i overlap the ballspawner's ball, this is just a static mesh, not the actual ball that has physics for rolling etc.

The fire event gets fired before any SpawnActor node gets fired (because the SpawnActor node is behind the fire node), but this isn't set in stone, when i just remove or add random nodes, sometimes it's fixed, sometimes it just moves to another action event.

I've upgraded from 4.1.1 to 4.2 and the ball object type still is in the project settings.

I will post a link to the zipped project whenever you're ready. I don't want the link to be visible for too long.

avatar image Ben Halliday STAFF Jun 07 '14 at 03:45 PM

I'll be in the office for another 6 hours or so today. I should get an email as soon as you post it here, and I'll let you know as soon as I have it. Thanks!

avatar image Rens2Sea Jun 07 '14 at 03:50 PM

Here it is.

Simply walk over the ballspawner and see the Fire action event be triggered and a second later another time which actually launches the ball.

Edit: link removed.

avatar image Ben Halliday STAFF Jun 07 '14 at 03:56 PM

Okay, great, got it. I'll let you know after I've had some time to look around in it.

avatar image Ben Halliday STAFF Jun 07 '14 at 04:36 PM

I haven't had a lot of time yet, but I am seeing some strange behavior in this project. Before I go any further, can you tell me whether this is a purely Blueprint driven project or if you've added any custom c++ to it? Also if you've altered source in any way?

avatar image Rens2Sea Jun 07 '14 at 04:41 PM

This is pure blueprints based on a blank empty project with starter content. There has been no alterations to the source or any c++ code.

avatar image Ben Halliday STAFF Jun 07 '14 at 07:12 PM

On a hunch, I removed all the dodge input nodes, the MoveForward and MoveRight nodes, and the Fire node from the Character's EventGraph. I then went to Project Settings > Input and deleted each of those Inputs. I recreated them, and used them each in the EventGraph. Works perfectly now, as far as I can see. It doesn't even have a problem with the WASD keys being mapped to multiple inputs.

Give that a try. It's possible it's just remembering things it shouldn't.

avatar image Rens2Sea Jun 07 '14 at 09:04 PM

Yeah i guess that should work, but i already had the bug disappear in some way, don't know how that happend, guess by just adding/removing some nodes. Lets just hope it doesn't come back now. :)

avatar image Ben Halliday STAFF Jun 09 '14 at 08:22 PM

Let me know if the problem pops back up again. Hopefully it won't!

(comments are locked)
10|2000 characters needed characters left
Viewable by all users

Oh wow, this is one of the weirdest things ever.

Apparently the InputActionLeft event (bound to 'A') on my blueprint gets called when the ball touches the character. Take a look at the screenshot: i am pressing no keys, but the event still triggers.


bug2.jpg (513.7 kB)
more ▼

answered Jun 03 '14 at 08:31 PM

avatar image

48 6 11 13

avatar image Rens2Sea Jun 03 '14 at 09:08 PM

When i remove the InputActionLeft event it fires the InputActionRight, removing that one fires the backwards variant, and removing that one fires the forwards variant. Finally when i remove that one everything behaves as normal.

(comments are locked)
10|2000 characters needed characters left
Viewable by all users
Your answer
toggle preview:

Up to 5 attachments (including images) can be used with a maximum of 5.2 MB each and 5.2 MB total.

Follow this question

Once you sign in you will be able to subscribe for any updates here

Answers to this question