Distortion, Animation Raymarching

这节课的主要目的是对uv进行操作，实现一些动画的效果，实际就是采样的动画

struct texDistort
{float2 texScale(float2 uv, float2 scale){float2 texScale = (uv - 0.5) * scale + 0.5;return texScale;}float2 texRotate(float2 uv, float angle){float2x2 rotationMatrix = float2x2(cos(angle), sin(angle),-sin(angle), cos(angle));return mul(uv - 0.5, rotationMatrix) + 0.5;}float2 texDistortion(float2 uv, float time){float angle = atan2(uv.y - 0.5, uv.x - 0.5);float radius = length(uv - 0.5);float distortion = 4 * sin(3 * radius + 2 * time);return texRotate(uv, distortion);}
};

主要的变化公式，这里主要注意hlsl中因为是列优先存储所以右乘会更加的快速。这里列举了三种变化方式

缩放

旋转

记得转为弧度制radians()

动态旋转

struct texDistort
{float2 texScale(float2 uv, float2 scale){float2 texScale = (uv - 0.5) * scale + 0.5;return texScale;}float2 texRotate(float2 uv, float angle){float2x2 rotationMatrix = float2x2(cos(angle), sin(angle),-sin(angle), cos(angle));return mul(uv - 0.5, rotationMatrix) + 0.5;}float2 texDistortion(float2 uv, float time){float angle = atan2(uv.y - 0.5, uv.x - 0.5);float radius = length(uv - 0.5);float distortion = 4 * sin(3 * radius + 2 * time);return texRotate(uv, distortion);}
} tex;
float4 color = Texture2DSample(texObject, texObjectSampler, tex.texDistortion(uv, time));
return color;

更多的变化

struct texDistort
{float2 texScale(float2 uv, float2 scale){float2 texScale = (uv - 0.5) * scale + 0.5;return texScale;}float2 texRotate(float2 uv, float angle){float2x2 rotationMatrix = float2x2(cos(angle), sin(angle),-sin(angle), cos(angle));return mul(uv - 0.5, rotationMatrix) + 0.5;}float2 texDistortion(float2 uv, float time){float angle = atan2(uv.y - 0.5, uv.x - 0.5);float radius = length(uv - 0.5);float distortion = 4 * sin(3 * radius + 2 * time);float primDist = sin(6.0 * angle) * distortion;return texRotate(uv, primDist);}
} tex;
float4 color = Texture2DSample(texObject, texObjectSampler, tex.texDistortion(uv, time));
return color;