Альфа свойства имеют весьма широкий спектр применения.
The property also affects alpha testing, which can increase performance and alleviate the need for the sorting of alpha blended objects.
NiAlphaProperty enables or disables alpha blending based on vertex color alpha values and texture alpha values. It also allows the source and destination blending functions to be set, enabling lighting-style effects (and other special blending effects). Finally, the property allows alpha testing to be enabled or disabled and the alpha testing function and reference value to be set. Alpha testing may be used to increase the performance of applications that use alpha blending to implement binary transparency. It may also be used to avoid the need for back-to-front drawing of some alpha blended objects.
