Blur postprocess different on iPadMini and iPadAir


I am using the “FastBlur” post process shader from the Pro Image Effects pack. However I have noticed that when I run on iPad air it matches my PC and OSX builds perfectly but on the iPad Mini the blur shader causes everything to get much brighter.

I have isolated it to this shader by running no other effects. from looking over the shader code it seems to be doing a standard gaussian blur so I’m thinking it may be a precision issue with the weights adding up above 100%?

Has anyone else seen this issue before and is there a known workaround to get consistency on iOS?



Ok I figured this out, In case anyone else has this issue it is because the downsample is using fixed4 precision. This is not high enough for some devices. upping it to half4 fixes the problem