solved Occlusion Queries bug

[alexoy]

Hi,

Probably there is a bug in occlusion queries - http://www.babylonjs-playground.com/#QDAZ80#15

Here a label is a thing that appears/disappears depending on the visibility of a sphere. I've noticed Occlusion Query takes into account only meshes that were created before it was enabled. If I add a box later - BJS doesn't understand that a sphere is behind the new box and my label stays visible.

In my demo - in the beginning the label is not visible because the sphere is not visible, it's good. However, if you go to the right behind the box - label will always be visible.

 

Is it normal and can be configured somehow or it's a bug?

[Guest]

Hello I'm glad to say that this is not a bug

By default opaque objects are rendered in creation order but you need them to be rendered front to back if you want to leverage occlusion:

http://www.babylonjs-playground.com/#QDAZ80#16 (see line#53)

 

[alexoy]

@Deltakosh, thanks, it helped  and 2 new questions..

1. Of course about performance differences - will there be? Static list of meshes vs dynamic. Will it be reordered on every frame? (noticeable with a big enough list?);

2. For modelling I use Blender. When I set a texture on a mesh - there is a texture's setting whether to use "Alpha" or not. If I set "Use", even if my image is not transparent at all - occlusion queries say the label is still visible. If I uncheck "Use" - everything is fine and the label becomes invisible when behind this mesh. Is this an expected behavior?

[Guest]

1. It will on every frame but sort are pretty fast now on browsers

2. Yes as you are no more creating an opaque mesh but a transparent one which will not be processed by occlusion queries