[Fragment Shader] Random

傷城~ 2022-01-11 02:23 189阅读 0赞

The Book of Shaders - Generative designs - Random\[1\] 学习笔记.

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# 1. Random #

R a n d o m ( x ) = f r a c t ( s i n ( x ) ∗ 6331.346237 ) Random(x)=fract(sin(x)∗6331.346237) Random(x)=fract(sin(x)∗6331.346237)  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0phbWVzaWth_size_16_color_FFFFFF_t_70]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0phbWVzaWth_size_16_color_FFFFFF_t_70 1]

# 2. Random 2D #

通过向量点积将二维向量映射为一维浮点数, 然后得到二维的随机函数 :  
 R a n d o m 2 D ( c o o r d ) = R a n d o m ( d o t ( c o o r d . x y , v e c 2 ( 12.9898 , 78.233 ) ) ) Random2D(coord)=Random(dot(coord.xy,vec2(12.9898,78.233))) Random2D(coord)=Random(dot(coord.xy,vec2(12.9898,78.233)))  
![在这里插入图片描述][20190619125110506.png]

# 3. 网格化 #

在调用 Random2D 前, 将 floor 函数应用于坐标.  
 R a n d o m G r i d 2 D ( c o o r d ) = R a n d o m ( f l o o r ( c o o r d ∗ 10.0 ) ) RandomGrid2D(coord)=Random(floor(coord∗10.0)) RandomGrid2D(coord)=Random(floor(coord∗10.0))  
![在这里插入图片描述][20190619125457692.png]

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## 参考文献 ##

\[1\] Patricio Gonzalez Vivo, Jen Lowe. The Book of Shaders. Retrieved Jan. 8, 2019, from [https://thebookofshaders.com/10/?lan=ch][https_thebookofshaders.com_10_lan_ch]

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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0phbWVzaWth_size_16_color_FFFFFF_t_70 1]: /images/20220111/7b58e82584f949b19f8b7a316de0ae12.png
[20190619125110506.png]: /images/20220111/746c80e96a5f4c6ca5c84e2d31becc49.png
[20190619125457692.png]: /images/20220111/6ffff14335f84130a53a17f78111496d.png
[https_thebookofshaders.com_10_lan_ch]: https://thebookofshaders.com/10/?lan=ch