将眼睛纹理的实际大小控制为设备默认分辨率的乘数。
A value of 1.0 will use the default eye texture resolution specified by the XR device. Values less than 1.0 will use lower resolution eye textures, which may improve performance at the expense of a less sharp image. Values greater than 1.0 will use higher resolution eye textures, resulting in a potentially sharper image at a cost to performance and increased memory usage.
When this property is changed, eye textures are always reallocated, which can be an expensive operation. For dynamically changing eye render resolution on the fly, consider using XRSettings.renderViewportScale instead.