How to do Sunbeam effect in GIMP?


#1

Original


#2

Sunbeam effect


#3

If somebody here use blender, there is something called sunbeam filter. Anybody know how to get similar effect in GIMP?
https://docs.blender.org/manual/en/dev/compositing/types/filter/sun_beams.html


#4

I use zoom motion blur, but the effect is not quite the same as sunbeam filter in blender.


(Mica) #5

You can copy the layer, apply the effect to the lower layer, then use the perspective adjustment to adjust the blur to your liking.


#6

Any suggestion to make the “tail” not blocky? You can see the 2nd post the sunbean fade out smoothly.


(Mica) #7

Gaussian blur might work.


(Bri) #8

You could also try a layer mask to fine tune how the edges of the tail fade out.


(http://4232.cf) #9

gimp + gmic -> Lights and shadows -> Light rays

Lamentably, it can not have X and Y in negative


(Tobias) #10

I would try the linear blur:

https://docs.gimp.org/2.8/en/plug-in-mblur.html


#11

Hey, thanks that is awesome.
But you are right cannot change x and y more than 100% is sad, almost make it useless.


#12

I tried linear blue but it blur in two direction rather than 1.


(http://4232.cf) #13

I modify the canvas and displace the figure afterwards go back to cut

ping @David_Tschumperle


(David Tschumperlé) #14

Just changed the slider range for filter ‘Light rays’. It should appear in 30 minutes or so in your plug-in after a filter refresh (if you’re running G’MIC 2.2+).
Anyway, this filter has not been coded initially for a range outside [0,100]%, so some smoothing artifacts appear with those out-of-range values.


#15

This is what I cobbled together. It is kind of buggy. Edit: added more orientations.

PS I added the code in the G’MIC exercises thread here ↓


G'MIC exercises
(http://4232.cf) #16

That effect used?


(http://4232.cf) #17

I thought in [-100,100] or [-∞,∞]


#18

Yep, if the number is negative or more than 100 then there are visible artifact.
Maybe take some code from Blender sunbeam filter node?


(http://4232.cf) #19

I want to something to cross gimp with blender
“ora” maybe http://registry.gimp.org/node/18435
and https://github.com/ndee85/coa_tools/


(David Tschumperlé) #20

Not surprising, the initial code has not been designed with this range of values.

If someone wants to translate it as a new G’MIC filter, I’ll be happy to replace the existing Light Rays filter if we get more features with the new one.