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Flickering Light

Submitted by killbourne on Thu, 06/23/2011 - 22:57

Hey all
I did a little test after seeing a snippet of code posted by Mr.Admin here > http://www.gamestart3d.com/content/lights-shaders-and-candles#comment-864

I managed to get the diffuse intensity as well as the range size to flicker. Nice :)

Its not perfect. It looks more like a strobe light than a candle, but the idea is there. Hope you guys like!!

Here is the link to the vid on vimeo :) >> http://vimeo.com/25518085

and here is the code snippet used :)

  1. 	function	OnUpdate(item)
  2. 	{
  3.  
  4. 	local light = ItemCastToLight(item);
  5.     LightSetDiffuseIntensity(light, sin(Deg(g_clock) * 0.1) * 0.6 + 0.5);
  6. 	LightSetRange(light, sin(Deg(g_clock) * 1) * 0.6 + 0.5);
  7. 	}
Mr.Admin's picture

Mr.Admin

Thu, 06/23/2011 - 23:15

Nice!

Yes, it will be hard to make a sin function behave like a random flickering, I can propose you the following:

  1. class	New_Light
  2. {
  3. 	current_intensity	=	0
  4.  
  5. 	function	OnUpdate(item)
  6. 	{
  7. 		local light = ItemCastToLight(item);
  8. 		local new_intensity = Rand(0.1, 1.25)
  9.  
  10. 		current_intensity = current_intensity + (new_intensity - current_intensity) * 0.05
  11. 		LightSetDiffuseIntensity(light, current_intensity);
  12. 	}
  13.  
  14. 	constructor()
  15. 	{
  16. 		current_intensity = 1.0;
  17. 	}
  18. }

What this does is basically take a random number between 0.1 and 1.25 each frame and gradually ramp the current_intensity variable toward this value. You can tweak the 0.05 value to further smooth the transition and increase the intensity range (in the random call) to increase the effect.

killbourne's picture

killbourne

Fri, 06/24/2011 - 11:42

Thanx for this.
This will make learning squirrel a lot easier as I find it much easier to learn by doing rather than looking at a bunch of explanations as to what the code means then trying to put it all together [such as with the squirrel site and docs :( ].
I suppose this is because I have no formal knowledge on coding. Smaller snippets of code that do a specific function are easier to understand thus making it easier to learn :)

I don't want to make you feel rushed, but hows the new release looking? :p Im bot eager and excited to get some of my Cinema 4D models into Gamestart.

Mr.Admin's picture

Mr.Admin

Fri, 06/24/2011 - 13:37

Yes, I think I need to make some really simple tutorials.
But days are short...

Anyway, I hope to release the updated version tonight ;).

François Gutherz's picture

François Gutherz

Fri, 06/24/2011 - 15:32

Yaye ! A new version :)
Killbourne, I can't wait to see your Cine 4D stuff running in GameStart :D~~~