Getting a fog of war effect

Hi, I want to achieve fog of war effect like this:

I got a code for changing alpha of fog, but I need to first render ground and buildings, and then fog, beacuse fog is lower than buildings.

I was trying to change renderpasses, techniques, like here: How to control render order?
But the objects are still rendered above fog and I dont see transparency on texture

Now I made two viewports and cameras with different view masks but can’t get to render them at the same time (or I render one and second is covering firsts render), I have either only fog or objects and map. I need to somehow set the fog camera to render only fog object and not background, but how?

btw. I’m new to this engine, but I really like it, good work guys.

one way to achieve the fog of war is to use blend modifiers on the terrain vertices - take a look at how the terrain shader uses ‘blend mapping’ to mix n input textures in the fragment shader
basically, we paint vertex colours, and give the colours a meaning…

If your fog consists of 3D geometry you might get away with setting a depth bias in its material akin to:

<depthbias constant="-0.0000023"/>

Also, welcome to the forums!

@Modanung That works. I just have to decrease that value a bit, many thanks!

Lucky you, I needed to paint vertex colour for another purpose, which the editor does not support well - material properties on terrains for sound effects let alone physics - I feel I am reaching the end of the stuff that Urho supports out of the box