Imagination PowerVR SDK Blog

noise4


#1
Is noise<n>(vec<n>) supported?

 

Any guidence is appreciated.

 

Failed to compile fragment shader: Compile failed.
ERROR: Invalid call to function noise4: extension OES_standard_noise is not enabled.
ERROR: 0:1: 'assign' :  cannot convert from 'float' to '4-component vector of float'
ERROR: 2 compilation errors. No code generated.

powervr/omap3035
d1mbu1b2010-07-08 16:42:02

#2

No, the noise functions are not part of GLSL ES.


#3

thanks for the reply.
noise is part of The OpenGL ES Shading Language
It was just made ‘optional’ in version 1.00 revision 17 (pages 9, 11)
http://www.khronos.org/registry/gles/specs/2.0/GLSL_ES_Specification_1.0.17.pdf

Does PowerVR/SGX have any random number generator available using GLES 2.?
I am hoping someone can provide guidance on how to get around this.
I am using it for modelling/simulation.
I was hoping there is a lightweight solution that the community may be converging on.


#4
d1mbu1b wrote:
thanks for the reply.noise is part of The OpenGL ES Shading LanguageIt was just made 'optional' in version 1.00 revision 17 (pages 9, 11)http://www.khronos.org/registry/gles/specs/2.0/GLSL_ES_Specification_1.0.17.pdf

It was made optional in the first revision of the spec, then moved to an extension in revision 10, so it's not part of the core language spec any more. I am not aware of any OpenGL ES 2.0 implementation that supports the noise extension.



There are various ways of using textures to get noise with different properties. What are your requirements?




#5

Thank you. I’m looking into the simplex example now.

Initially, I only need to give the appearance of noise for proof of concept and unit testing.
A full up noise algorithm will be needed in order to obtain 'real' results.

A simple psuedo random number will suffice for now.

If you all had an undocumented or burried  poor mans rand(), randn(), that would be great.


Thanks for your help.
d1mbu1b2010-07-09 19:54:17