Polygon two sides

Two sides refer to the common practice in 3D modeling where only one side of the model's surface is rendered. This is typically the side visually displayed. However, when rendering both sides, the system needs to perform double the graphic work, which can affect performance.

Some platforms discourage the use of Two sides to maintain optimal performance. In addition, there are instances where using Two sides can be a reason for rejection during evaluation.

1. Only ensure that the backside of the polygon is not visible.

2. For simple cases, as shown in the picture, the most efficient way to save on polygon count is to block the holes.

After the work, please organize the mesh's UVs and textures.

For further details, please refer to the [topology guidelines].