ios - Why do subsequent update calls to GPUImageUIElement result in black output? -

ios - Why do subsequent update calls to GPUImageUIElement result in black output? -

problem: i'm trying apply gaussian blur changing uiview , display live blurred result using gpuimage. many of gpuimage's filters work perfectly, gpuimagegaussianblurfilterbehaves differently in unusual way. after sec update phone call of gpuimageuielement without re-instantiating input, , filter, resulting output black , blank.

example:

- (void) viewwillappear:(bool)animated { // blurinput --> blurfilter --> bluroutput gpuimageuielement *blurinput = [[gpuimageuielement alloc] initwithview:self.changingview]; gpuimagegaussianblurfilter *blurfilter = [[gpuimagegaussianblurfilter alloc] init]; gpuimageview *bluroutput = [[gpuimageview alloc] initwithframe:self.view.frame]; [blurinput addtarget:self.blurfilter]; [blurfilter addtarget:self.bluroutput]; [self.view insertsubview:self.bluroutput]; [blurinput update]; }

what happens: @ point blur working, subsequent phone call [blurinput update] (ie. underlying self.changingview when updates) results in bluroutput view turning black …unless re-instantiate blurintput/blurfilter, add together targets again, , phone call [blurinput update]. isn't necessary many of gpuimage's other filters.

notes:

the part of changingview updating it's gradient layer (cagradientlayer) in actual code 3 gpuimage variables held strong ivars.

ios objective-c gpuimage