HLSL Complex Shapes With For Loops

制作一个动态的cycle的动画材质

首先我们使用hlsl来写一个圆

// The below expression will get compiled
// into the output of this node
float result = 0.0f;
for(int i = 0; i < nSize; i++)
{
  float angle = 2 * (i / nSize) * 3.14;
  float2 pos = center + radius * float2(cos(angle), sin(angle));
  result += length(pos - uv) < size;
}
return float3(result, result, result);

加入偏移让圆动起来

float result = 0.0f;
for(int i = 0; i < nSize; i++)
{
  float angle = 2 * (i / nSize) * time * 3.14;
  float2 pos = center + radius * float2(cos(angle), sin(angle));
  result += length(pos - uv) < size;
}
return float3(result, result, result);

多指针旋转

也就是沿着半径去增加点的数量

float result = 0.0f;
for(int i = 0; i < nSize; i++)
{
  for(int j = 0; j < nCopy; j++)
  {
    float angle = 2 * (i / nSize) * time * 3.14;
    float2 pos = center + radius * (j / nCopy) * float2(cos(angle), sin(angle));
    result += length(pos - uv) < size;
  }
}
return float3(result, result, result);

后续可以按照自己的需求修改