why all the things flashing in the scene in BGE

[hitliu]

as you see,in the BGE,the bulidings and the road are flashing when my car is moving in the scene. All the models are textured and have no materials. the scene is in textured mode.
I donnot know how to solve the problem. have you ever enconterd this ? thanks!

[Monster]

The question is what is under the road/behind the walls.

I assume you have faces behind other faces that are too close together. What distance they can have depends on the clipping distance of the camera. As larger the distance as larger the minimum distance. (Typical scenario: like pictures on the wall)

do not do this:

or this

but this:

• If you have twoside enabled at the models, switch it off.
• Remove doublicate vertices in edit mode.
• Increase the distance between faces pointing into the same direction and/or decrease the clipping distance of the camera.

last but not least:

• try it at an different PC. It could be a graphics problem too.