Hide some region of pixels

Hello.

I've made 3D model equipment system.
My character can wear serveral parts like pants, boots, shirts, hats, etc.
And some combinations have conflict, for example long boots and pants.

Therefore I want to hide some region of pixels.(Some games use it)
1st, To make box in each model for selecting hidden region by 3ds Max.
2nd, Copying vertex positions to uv3 channel.(vertex position is changed by animation)
3rd, Calculating all boxes for obb(oriented bounding box).
4th, When character equips parts, send box information to shader.
5th, In shader, make sure that vertex position(in uv3 channel) is inside box.

But in second step, vertex and uv values are different in shader even same in cpu.
Just change UnityObjectToClipPos(i.pos) to UnityObjectToClipPos(i.uv3_VertexPos), but all transformation (position, rotation, scale) are difference.
I also used renderer.rootBone.TransformPoint, renderer.TransformPoint through copying position to uv, but rotation and position are difference(Scale is right).

How can I send right vertex information to uv?
Or Is there another good way to hide some regions?

 

Wow! This is a really cool and complex concept to mask hidden parts of a mesh that overlap other parts of a mesh.

The shader process you are attempting is most likely more optimal - if you can figure it out - and is a very cool idea, but I have no input on how it can be fixed to work correctly.

I'm pretty sure there is no built in solution for this - however there might be an alternate way to set up a system in engine that swaps a transparent mask - depending upon the other clothes that are applied to the character.

Using the example you provided - boots and long pants.
If the character is wearing boots and long pants - the system would load up this transparent mask for the boots, essentially hiding the polygons you do not want to overlap with the pants.
Dark grey used in place of black just for example purposes.




When the player is equipped with longer pants the system would load up this transparent mask for the boots.


When the player is equipped with shorter pants the system would load up this transparent mask for the boots.


And when the player is equipped with shorts and boots - the system would load up either a complete white transparent mask or just not load a mask map at all because it is not needed when the character is wearing shorts with boots.

 

If it only depends on the height, y position.
You can just disable height above that value.
It will be a Y cut shader.Up down or down up order.
X and Z may be the same

 

Thanks for replying.
But it's not depend on the height. Boxes can be exist any position and rotation.