[unity shader ablation effect _ case sharing]

1. Implementation logic

The ablation effect is mainly based on Shader Medium clip() function , That is, transparent test function , stay ASE It's called in Chinese “Opacity Mask”.
The ablation effect is based on a “Noise” Texture map can be calculated ,“Noise” The gray range of texture image is [0,1] .
Start by adding a value to the texture map “v = 1” , Make the interval of gray value on the texture become [1 , 2].
Then gradually reduce v value , When “v = -1” when , The gray value on the texture becomes [-1 , 0].
Transmit the change process of texture to Cilp() Function can realize the effect of gradual ablation of the model , And through v To control the degree of ablation , The range of values is **[-1 , 1]**.

2. Resources to prepare

“Noise” Texture map is in Photoshop Drawing in .
The method is as follows ：

1. stay Photoshop Create a 512*512 The gray image .
   

2. Click on the filter -> Rendering -> cloud , Generate for the current graph Noise texture .

3. Click menu image -> Auto tone , Use the darkest pixel in the image to achieve 0、 The brightest pixel has a gray value of 255.