The problem of grid black line in model after "Unity" turns on MSAA

Problem: The model of the role, after the MSAA is turned on, some perspective will appear the problem of the model grid black line.

After many attempts, the final question is locked in the calculation of the POW function in shader.

The efficiency of the POW function is inefficient, each time the operation will be lost precision, which will lead to some boundary values, such as a vector click operation close to 0 or 1 of the value, in the calculation process due to the loss of precision more serious problem of numerical cross-over.

The curve solution is to offset the loss of precision in the operation by adding a small floating-point number to the parameter of the operation +/-.

As to why this problem occurs after the MSAA is opened, it is necessary to study the specific implementation of MSAA.

The problem of grid black line in model after "Unity" turns on MSAA