clip/hole geometry

[romain.janil]

Hi , I think it's already been asked but I have a special use case which would benefit if something like that  could be done:

is it possible to clip/hole a geometry having many surfaces/materials (eventually with paired material bit mask) by another mesh (it can be a simple non uniformly scaled cube primitive)?

A bit like hole decal for terrain, all geometry/surface/materials (matching clipping cube bit mask) and  inside this cube wouldn't be rendered .

Thanks for any advice.

Romain

 

[silent]

Hi Romain,

I'm afraid out of the box there is no such functionality available. Probably you can code something like that, but hard to predict how complex would be such solution.

The closest built-in object is Occluder, but it's hard to control the exact objects / surfaces that it should hide.

Thanks!

[romain.janil]

Hi Silent, yes I guess too it might become really complex (ie kind of real time soustractive boolean, or maybe something else shaderwise, I'll see ) when trying to make something generic.

I'll also investigate on the "content" side to see if it's possible to streamline/automate this as a process in a gis tool. Typical use case is for removing some parts of 3D tiles (several thousands) and replace (buildings, trees ) with some better version on some places while keeping the rest untouched) As you may know, this kind of data (photogrammetry( or lidar) acquired) is generally a polygon soup, segmentation of the data is still an heavy process.

i'll dig in all that...

Thanks 

[Amerio.Stephane]

Hi,

We have a similar need to cut holes in geometry, to "see through" into a object. We kinda solved it by having all materials of the mesh to be cut inheriting from a common shader graph, with alpha test, which would simply turn the alpha to 0 when the pixel being rendered is inside a given cuboid (passed to the shader).

For terrain though, no such possibility exists, you have to use a classic "terrain hole".

[romain.janil]

Hi Stéphane,

thanks for the tip, I'll dig into that.