models switches on and off

General Discussion
1

In a large database, I include a number of separate egg models with a larger switch distance (2000 meters). The farplane is defined at 2500 meters. When I move through the database some of these models seem to be switched on and off between cycles. When I am stationary they are rendered, while when I am moving they are ‘flickering’: one frame they are rendered while the next frame they are not rendered. When this occurs I am definitely closer than 2000 meters. If I am closer than, say, 300 meters, they are rendered all the time.

What could cause this switching on and off?

2

Hmm… do you perhaps have vsync disabled? If so, does it go away if you enable vsync in Config.prc?

3

Whether I enable of disable vsync, it doesn’t matter. I tried both. Disabling vsync only reduces framerate.

4

Could you be experiencing the same problem reported here? What is your near plane set to? Make sure it is not unreasonably small.

Or, perhaps you are experiencing z-fighting, the kind of flickering effect you get when you have two objects that occupy exactly the same space?

David

5

The near plane was set to 0.5. I increased it to 1.5 and the problem is still the same. The are no other objects near the ones that flicker. One is a large building and the others are hills.

6

Hmm, well, I don’t know what might be causing this flickering; but one idea to help narrow it down is to add the line:

fake-view-frustum-cull 1

to your Config.prc file. This will draw things in red wireframe when Panda believes they should be culled. (It may adversely affect your framerate, but this is just for a test.)

If setting this option makes your objects change temporarily into red wireframe, then we know it’s a problem with culling for some reason. If, instead, the objects still disappear the same way they did before, then it must be something else.

David

7

Looks like z-fighting to me. They vertices/faces don’t have to be in exact same position when the camera is too far from them

8

Thank you for your suggestions. I found it: the sky dome was smaller than the distance to these models, while setDepthWrite of the skydome was set to 0. I have set the DepthWrite of the skydome to 1 and then the flickering was solved. So this problem is solved.