Techniques for breaking up edges of intersecting geometry

Lunarcy

Hi all, I'm new to the forum but not CG.  By no means an expert, I seek your collective help with something.

As the title states, do you know any good techniques for breaking up the edge where two bit of geometry meet?  Particularly where the bottom of a wall meets the ground.  I don't mean with textures as this would leave a sharp edge.  Something that could fake the accumulation of grease of dirt, just to roughen up the intersecting edge to blend them together a bit.

Cheers

Klunk

"breaking up" an edge with geometry would require so much geometry as to be mostly pointless when it's relatively painless task and more convincing to use textures.

Neox

there are plently of ways how to tackle this, 

decals are an option, maybe using vertex masked dirt shader stuff, you could cover the transition with gras, dirt, rubble, rocks meshes etc.

maybe it would help seing what you like to achieve in your specific case to help a bit better.

Lunarcy

Thanks for the replies.  I'm working on a dirty street scene and thinking of attempting photorealism.  It's those hard edges close to the camera where the wall meets the floor that ruin the illusion I find

dimwalker

Inverted AO as a mask to blend in some dirt might work.

Klunk

is this for real time or a rendering ? 

Ruz

texture blend?

Alex_J

besides props and scatter to cover the edge, the only thing I know of to do texturing wise is that the color and value at the intersection has to match in order for the eye to not see it.

so in unreal for example people do some techniques to bleed some of the terrains textures onto objects: https://www.youtube.com/watch?v=xYuIDFzKaF4

Lunarcy

It's not for real-time rendering, although the technique in the video Alex_J posted would be perfect if possible in a render engine like v-ray.  Having geometry at the intersection who's texture could be blended between the wall and floor texture would be the ideal solution.  

Klunk

so what app are you using ?

Lunarcy

Klunk said:

so what app are you using ?

I'm using Cinema 4D with V-Ray

Eric Chadwick

You'll want the Distance Node for effects like Alex_J pointed to 
https://docs.chaos.com/display/VC4D/Distance+Node

Lunarcy

Eric Chadwick said:

You'll want the Distance Node for effects like Alex_J pointed to 
https://docs.chaos.com/display/VC4D/Distance+Node

That sounds like what I'm looking for. Thanks Eric, and everyone else for their suggestions.  I'll check it out