Master Material Issues

Hey everyone,
I am a uni student currently working on a project with some friends in UE4, and I have been working on a master material to provide us with some easy variation and functionality across the board. I’m primarily a 3D artist but I have been teaching myself how to work in the material editor for a while now, and I am hoping someone can lead me in the right direction here; as I have hit a wall of what I am assuming is incompetence.

I’m not sure if what I am doing is entirely too complex and there is an easier way, but what I am trying to achieve is a grunge overlay that doesn’t rely on the UV layout (we are using a trim sheet for most of the scene), that we can project over environment assets and add some colour variation and maybe implement a way to mask out areas of the overlay if necessary, as i don’t want it to cover the entirety of the assets.

So far i have set up two triplanar functions (mostly for extra customisation) with two separate masks that overlay a base diffuse.
The base diffuse has a 3 vector parameter set up to change the colour on the fly, and I have tried to do the same with the triplanar functions. There are some other parameters set up for opacity, strength, contrast and some static switches to invert the grunge maps.

The biggest issue I am having is that they don’t override the colours underneath and any colour I select in an instance seems to inherit the base diffuse’s colours somewhat, so it just ends up a weird combination of the two colours. Ideally it would ignore what is underneath and just overlay the new colour with the grunge patterns. Same issue with the second triplanar it just blends between all of them.

Any direction or help is appreciated, cheers.

Here is my current set up and an instance demonstrating the issue.
(Grunge maps are just placeholder and outrageous colours are just to see how far off everything is)

You could look into vertex painting to blend between your layers. The node for it in material editor is ‘VertexColor’ or something, then using the paint tab (where landscape, bsp, create tabs are) paint RGB values onto your meshes, then use that to mask out areas using the afformentioned node.

Theres tons of tutorials for it online. It kind of ends up working like how landscape material painting works, but you can paint every mesh differently too.

Thanks for the reply, I have thought about vertex painting, but this is a little more fast overlay so the environment artist doesn’t need to paint everything individually, might still implement that later if we need it but cheers. I ended up rebuilding it and getting it working with some direction from polycount; still need to get some of the custom parameters into it again but once it’s done i might post it up if anyone wants to take a look.

Ended up getting the dual triplanar masks working each with an opacity parameter and colour selection, here is the set up 6319d4e776400a8a7f179b62edc71d2074ff750d.jpeg