Portable hole with decals?

pixelquack

Instead of having some surface on an object with decals -- would it be possible to have an "invisible" surface that I can put on an Iray Decal node to create a hole in an object?
Like a movable opacity map element with 0 opacity?

barbult

An opacity map on a decal just hides part of the decal and lets the parent surface show through the decal. I don't know of any way to make a decal create a visible hole in the parent object.

Silent Winter

Only method I know (other than creating an opacity map specific to the object) is to use your decal with a bright green (or blue, or other colour not used elsewhere in the image) to do a 'green-screen' effect.

Project the shape of hole you want in green. Render. Do another render with the object missing and an 'inside' where the object was. Combine as layers in PS/GIMP and remove the green with colour-select and delete.

WendyLuvsCatz

since advanced iray node properties include mat, I am certain it could be scriptable but of course I totally lack the nerdy codey proweress to imagine how to do it

I can do it in Carrara 

create a shape layer and use an alpha map

richardandtracy

The biggest problem is that 'Toon Holes' (such as found in 'Who Framed Roger Rabbit?') aren't real and can't just be curled up in your pocket.

Much as we'd like them to be.

Regards,

Richard.

 

pixelquack

Opacity map is my next go-to, yes. Greenscreen approach isn't bad but if you invisible an object like the street level it will dramatically affect the rest of the image.

I have Gescon, and my results there are... hmmm... I always have an "broken" edge with a hard to include surface. 

What I'm up to is creating holes in walls and lead into a pipe here or a hole in the street for a man hole, which often enough I'd need the Thickener plugin to begin with.

I guess for open mesh streets the opacticy map really is the easiest way. If only one could paint those map in the viewport directly...