1
book of shaders有十幾個例子,他們設置顏色以複雜的方式瞭解如何在算法繪製成形函數的bookofshaders一章中設置顏色數學的工作原理?
color = (1.0-pct)*color+pct*vec3(0.0,1.0,0.0);
問題:
- 什麼他們PCT代表呢,你覺得呢?
- 爲什麼數學減1
(1.0-pct)
? - 爲什麼按顏色加上pct
color+pct
? - 你如何乘以一個數字和一個向量
x*vec3(0.0,1.0,0.0);
? - 爲什麼數學乘數和矢量?
完整代碼示例
#ifdef GL_ES
precision mediump float;
#endif
#define PI 3.14159265359
uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;
float plot(vec2 st, float pct){
return smoothstep(pct-0.02, pct, st.y) -
smoothstep(pct, pct+0.02, st.y);
}
void main() {
vec2 st = gl_FragCoord.xy/u_resolution;
// Smooth interpolation between 0.1 and 0.9
float y = smoothstep(0.1,0.9,st.x);
vec3 color = vec3(y);
float pct = plot(st,y);
color = (1.0-pct)*color+pct*vec3(0.0,1.0,0.0);
gl_FragColor = vec4(color,1.0);
}