Change colour of shadow in shadow-only material?

[MadeByJawns]

Hey, is there any way to change the shadow colour when using the shadow-only material, apart from using shadowGenerator.setDarkness() ?

If not, I'm guessing maybe I'd need to try extend the shader to include emissive? is that right? or is there a different / easier way I can have a transparent mesh that displays colored shadows?

This is so I can have a model with a blueish shadow displayed on page and be able to change the background page colour without also having to then match up the colour of a plane in the scene.

Any pointers on how to begin would be great!

[Guest]

Shadows are generating by masking the lights. They are not producing a color per se. They just block the light to add energy to the local mesh color.

So to produce colored shadow you will need to create your own shader that will compute the shadow level and will write the color you want accordingly

The idea would be to replace this line :

https://github.com/BabylonJS/Babylon.js/blob/master/materialsLibrary/src/shadowOnly/shadowOnly.fragment.fx#L49

by: vec4 color = myColor * clamp(shadow, 0., 1.);

 

[MadeByJawns]

Thanks for the insights Deltakosh!

Very interesting stuff, I've never done any shaders apart from using the material editor in Unreal so it's gunna be a bit of a learning curve I suspect, gunna do some reading on materials/shaders and give it a go when I have time :)