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"

Spawn particles based on texture

This might be a bit of a stretch, I googled with no avail. I figured it won't hurt asking.

Is there a way to drive the spawning of particles based on a texture or a material?

I'm trying to spawn particles based on an animated texture. The answer seems to be no and I can't find real alternatives to this.

Product Version: UE 4.12
more ▼

asked Jul 27 '16 at 02:53 PM in Using UE4

avatar image

88 3 7 13

avatar image Luos Jul 27 '16 at 02:56 PM

hello Vernocchi, can you perhaps tell me in more detail what you want to achieve? Perhaps I can help you, or know someone who can.


avatar image vernocchi Jul 27 '16 at 03:10 PM

Essentially I'm doing a pretty straightforward effect of having an object appear by animating an opacity mask (something similar to this: https://www.youtube.com/watch?v=6aflOXRrGTI). What I'd like to do is spawn smoke particles where the transition happens. There seems to be no way to do this other than perhaps using a moving invisible mesh to do it but it would not work with complex meshes.

Any ideas?

avatar image DamirH Jul 27 '16 at 04:06 PM

I am assuming your effect is similar to the one in the video, i.e. the transition goes in one direction. Well you most likely have a timeline or such to drive the current percentage of the transition (assuming it moves, i.e. the object burns away into nothingess). What you could do is use that timeline or whatever you have to drive a proxy collision box that roughly covers the transition area. It won't be pixel perfect but for purely cosmetic effects such an approximation is usually good enough.

avatar image vernocchi Jul 27 '16 at 04:42 PM

Ah, yeah that would be feasible but this would require a fairly complex collider on the mesh, right? Since I essentially need the outline of the sliced mesh. Thanks though, this points me in a good direction!

avatar image DamirH Jul 27 '16 at 09:01 PM

This really depends on how precise you need it to be. If you REALLY need a pixel perfect collision with the outline then this won't work for you. If you just want to fire off a smoke particle when the player "shoots at the transition" then this is bound to be good enough.

avatar image gldsgns Apr 11 '18 at 01:46 AM

I'd really like to know if there is a great answer for this. Emitting particles with a grayscale map or even procedural noise seems a powerful way to approach a variety of effects. Is there not a simple way to trigger emission based on image's RGB data and map particle spawn location via mesh UV coordinates?

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

0 answers: sort voted first
Be the first one to answer this question
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