Imagination PowerVR SDK Blog

Deferred Shading on iphone 3GS realy ?


#1

hi


Whether there is a sense to do it? Whether will be comprehensible FPSidarkstranger2009-08-10 05:04:31


#2

Rendering with POWERVR hardware is always deferred so in a sense this is always happening - what actual technique(s) do you want to implement?


#3

Hello! I’d like to implement deferred shading through the SDK but it seems like I’m missing a color attachment…

From my understanding, we can attach different texture to a fbo and access those with gl_FragData[X] but in gles 2.0, we only have this color attachment:

#define GL_COLOR_ATTACHMENT0              0x8CE0

#define GL_DEPTH_ATTACHMENT               0x8D00
#define GL_STENCIL_ATTACHMENT             0x8D20

Do you have any idea how I would write all necessary data to use deferred shading without using a second pass? (as far as I understand, we need at least 1 for normals, 1 for color and 1 for depth) Would it be possible to use the stencil attachment to keep the normals or something like that?

Any hints or ideas? Is that the right place to ask such questions?


#4

Multiple render targets are currently not supported in OpenGL ES 2.0, so this kind of algorithm currently cannot be implemented in a single pass. Depth and stencil attachments are specialised and don’t allow writing arbitrary values.