Instanced Drawing Bug

Hi, I'm a member of a 3D game engine development team. We've made many cool web game demos using our engine and here is our website: 成功案例 | Evil 3D引擎

Recently, we met a bug of instanced drawing when we trying to use this feature to improve the performance of our games. We found that if we call the drawTrianglesInstanced function only once, it functioned normally, but if we call the function multiple times, we will get weird, unexpected results. However, in games, many objects have to be drawn more than once(for example, the shadow map algorithm), so this bug has seriously affected the normal usage of this feature.

In order to help you check this bug, we modified a very simple Stage3D code from this tutorial: Adobe Developer Connection | Instanced Drawing in Stage3D

The .as file has been attached to Tracker . If you comment out line 143, you will get the result exactly the same as in the tutorial:

But if you uncomment this line, weird result will be got:

Hope you can fix this bug, thanks!