I submitted a new PR to your repo with some new features and bug fixes for the Blend Shader:
Notable features added:
- Params for adjusting noise values for dissolve blending
- Gradient color for fading edges of dissolve-blending or height-blending
- New BlendLayerEffect class, and 3 basic effects that can be added to a blend layer: TimedBlendEffect, HeightScanEffect, and HsvCycleEffect
- Added support for scaling a layer’s hue/saturation/brightness in hsv space with a new HsvScalar Vector3f paramater
- New ShaderBlendLayerManager class that handles dynamically adding and swapping layers, and will eventually handle prioritizing the render order as well as culling covered layers
- A new test case that lets you dynamically add/remove layers and effects (shown in the attached video). The interface is functional but still slightly sloppy and could still be improved
- Added a multiplicative blending mode that gives the option to combine the blend layer with the previous layer, rather than replacing it
And I also fixed a bunch of other small issues including the issue with tri-planar mode’s normal maps.
The only unresolved issue is related to using the BloomFilter, since the normal PBRGlow frag shader won’t work in this case. So unfortunately there is no bloom in this video. Otherwise I’m happy to say mostly everything else has ended up working out as planned.
Hopefully you’ll all enjoy this new demo video, and any feedback or testing of the source code is greatly appreciated 
