Lighting and shadows with Cocos2D and Box2D

1
votes

I am currently developing a game for iPad & iPhone using Cocos2d with Box2d. It would have been majorly cool to achieve a lighting effect like the one in this video:

http://www.youtube.com/watch?v=Elnpm-gNI04

and on this link:

http://www.catalinzima.com/2010/07/my-technique-for-the-shader-based-dynamic-2d-shadows/

I could have a go at trying to replicate the effect with Cocos2d and Box2d from the description in the link, but I am unsure if I would be able to get very far. It looks pretty advanced and heavy.

How can I achieve this in an "easy" way? Does anyone know of a Cocos2d-version of something like this, or do anyone have some pointers to point me in the right direction?

2
cocos2d-iphonebox2dbox2d-iphone
I think the article explains in detail how the shadowing works. I suggest you dive into graphics/shader programming and learn some basic structures and procedures required to get a better understanding. I'm unsure about the rendering capabilities of Cocos2D but I guess you should be able port the examples (especially since the source code is available). I wish you good luck! :) - Constantinius
Note: Cocos2D v1.x uses the OpenGL ES 1.1 pipeline, that means no shaders. Cocos2D v2.x will use OpenGL ES 2.0 which allows you to write shaders. However, Cocos2D 2.0 is currently only available as a very early alpha version. - LearnCocos2D

2 Answers

4
votes

http://code.google.com/p/box2dlights/ I have succesfully made dynamic light library that use box2d geometry and rayCasting. My library work under gles1.0 and gles2.0 and use libgdx as framework. This is peformant enough for giving dynamic real time lights to 2d games for mobile devices. I can help with porting that to Cocos2D. Basics are darn simple. It was under 100 lines when I first hacked it working for my own game.

Example: Point light shoot from center n number of rays around it and record the closest collision points. These collision points are used for mesh that is colored with gradient and drawed with additive blending.

0
votes

Try to look at this link.

http://www.cocos2d-iphone.org/forum/topic/27856

He successfully added simple dynamic light using cocos2d + chipmunk following the technique that Catalin Zima used. Please note if you download his project and try to compile iOS build, then remove "Run Script" build phase as you may experience script didn't found error. More info to remove such phase can be seen here.