Regarding the issue of rendering direction when cesium adds video materials to polygons

I now want to make a visual cone and add a video image at the end of the cone. I hope this video image can always be upward like adding it to a wall. But in reality, there may be errors in the direction when the video is successfully added. Perhaps some internal graphics processing during the rendering process resulted in different orientation calculations, and I am not very good at this. Can someone help me? thank you very much indeed