Hi @Thibault_Bruyere, thank you for responding so quickly!
Eventually fixed it up by extending the vtkForwardPass twice and modifying the renderers/layers to focus each pass where I wanted it to apply. Then just put each pass on the view in sequence. Worked a treat, thank you again!
let pass0: Conv2DPass = renderer0Only.newInstance()
let pass1: Conv2DPass = renderer0Plus.newInstance()
if (state.conv != null) {
if (state.conv.gaussianBlur)
pass0 = applyPass(gaussianBlurPass, pass0)
pass0 = applyPass(getMaskPass(state.conv.enhancement), pass0)
}
this.view.setRenderPasses([pass0, pass1])