Occlusion problem through arrowslits ( bug ? )

Unity Engine
1

Hi all :slight_smile:

First of all, lemme just introduce my whole scene:

5430627--552954--around_the_city.jpg
5430627--552954--around_the_city.jpg1915×970 903 KB

A large medieval city in wich you can evolve at human scale through a 1st person view…

A medieval city has arrowslits in its walls:

5897549--629162--arrowslit1.jpg
5897549--629162--arrowslit1.jpg1519×654 306 KB

My problem comes from occlusion system, culling things that should be seen through arrowslits.

With the 2nd pic, it seems everything works fine from this side of the wall.
Things to be culled are culled and things to be seen are visible.
The problem comes when you look through the arrowslit from the other side of the wall:
On this pic, all is okay:

5897549--629165--arrowslit2.jpg
5897549--629165--arrowslit2.jpg1519×654 109 KB

but on this one ( slight move of the camera from the previous pic ) the object behind the arrowslit disappears:

5897549--629171--arrowslit3.jpg
5897549--629171--arrowslit3.jpg1519×654 104 KB

The height of this ‘hole’ is usually between 0.8 and 2m
and the width uses to be between 0.08 and 0.15m

Of course i set up the min hole size to 0.04 in the occlusion bake params but even with this value, it appears umbra is unable to see through those arrowslits…

Anyone got ideas of what’s going wrong please ?

Thanks in advance and
happy unitying !

2

Bump ! :slight_smile:

Anybody for some advices please ?

3

okay.
I conclude noone uses U3D occlusion system…

Too bad dev team wasted so much time on unused things :frowning:
Seems to be so usual :stuck_out_tongue:

Happy unitying !

4

Have you tried adding occlusion portals in each arrow slit? I believe they are designed to do exactly that: force the occlusion system to consider holes that would otherwise get ignored.

5

Salut @Tartiflette :smile:

To be honest i never caught the purpose of portals in occlusion system.

I managed to solve my problem by lowering the smallest hole size but as expected, the occlusion data went from 7MB to 23MB :confused:
With there setting things seem to work properly but am kinda deceived as most of the things i got to occude and most of my occluders are in a scal of several tens meters :confused:

I gonna give a try on portals…
On simple scene and will report my results here.

Thanks @Tartiflette for the idea :slight_smile:

Happy unitying !