Grass - Blade
Given a mesh consisting of 20 vertices, initially all vertices are located at the origin. You need to move the vertices using their index to form a block on the screen with a total height of 1, consisting of 9 equal rectangular segments.
Then change the width quadratically based on the current height, starting from 0.1 at the base and decreasing to 0 at the top.
attribute int index;
void main() {
vec3 pos = vec3(0.0);
gl_Position = projectionMatrix * viewMatrix * vec4(pos, 1.0);
}
