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@darkproject 2020-02-13T11:30:12.000000Z 字数 5107 阅读 877

TA测试题记录

记录

5道选2道做，自身美术实力的确还需要加强。有道比较不错的程序化建模题(待补中，打算用houdini和引擎内各实现一遍)。花了1天时间学习了py语法和pil库(查资料累死咯)据说第三问可以直接用pil库做，不过没有找到相关api，自身结合竞赛图论知识勉强怼了出来。

仅使用Pil库进行图片处理，r通道高斯模糊设置模糊半径，g通道边缘检测并设置阈值0.5，b通道根据g通道计算闭合区域，并对闭合区域咦其中心y值（纹理坐标系）填色。

  1. import os
  2. from PIL import Image
  3. from PIL import ImageFilter
  4. dx=[-1,0,0,1]
  5. dy=[0,-1,1,0]
  6. xmin,ymin,xmax,ymax=[],[],[],[]
  7. #思路:用PIL内置filter进行高斯模糊解决第一问
  8. #用PIL内置filter进行边缘检测,遍历图片对每个纹素进行阈值判断解决第二问
  9. #第三问:在边缘检测后的二值化图像求取闭合区域,通过深度优先搜索遍历黑色区域(非边缘部分)
  10. #对每个连通分量进行标记,然后记录xmin,xmax,ymin,ymax得到连通块的bbox求取中心坐标
  11. #栈模拟dfs防止溢出得不到结果,因为离线操作不太考虑时间效率。
  12. class node:
  13.     def __init__(self,x,y):
  14.         self.x=x
  15.         self.y=y
  17. class Stack:
  18.     def __init__(self):                        
  19.             self.items = []
  20.     def isEmpty(self):                         
  21.             return self.items == []
  22.     def push(self, item):                      
  23.             self.items.append(item)
  24.     def pop(self):                             
  25.             return self.items.pop()
  26.     def peek(self):                            
  27.             return self.items[len(self.items)-1]
  28.     def size(self):                            
  29.             return len(self.items)
  30.     def clear(self):                           
  31.         self.items = []
  33. #栈模拟dfs
  34. def dfs(x,y,label,img):
  35.     while(s.size()>0):
  36.         cur=s.peek()
  37.         flag[cur.x][cur.y]=label
  38.         xmin[label-1]=min(xmin[label-1],cur.x)
  39.         ymin[label-1]=min(ymin[label-1],cur.y)
  40.         xmax[label-1]=max(xmax[label-1],cur.x)
  41.         ymax[label-1]=max(ymax[label-1],cur.y)
  42.         s.pop()
  43.         for i in range(4):
  44.             next=node(cur.x+dx[i],cur.y+dy[i])
  45.             if(next.x<0 or next.y <0 or next.x>=width or next.y >=height): continue
  46.             if(img.getpixel((next.x,next.y))==0 and flag[next.x][next.y]==0 ):
  47.                 s.push(next)
  50. def threshold(t,img):
  51.     for w in range(0,width):
  52.         for h in range(0,height):
  53.             pixel=float(img.getpixel((w,h)))/255
  54.             if (pixel>t):
  55.                 img.putpixel((w,h),255)
  56.             else:
  57.                 img.putpixel((w,h),0)
  59. #记录相应的连通块及对应的bbox              
  60. def connected(img):
  61.     set=1
  62.     xmin.append(width)
  63.     ymin.append(height)
  64.     xmax.append(0)
  65.     ymax.append(0)
  66.     for w in range(0,width):
  67.         for h in range(0,height):
  68.             if(img.getpixel((w,h))==0 and flag[w][h]==0):
  69.                 s.push(node(w,h))
  70.                 xmin.append(width)
  71.                 ymin.append(height)
  72.                 xmax.append(0)
  73.                 ymax.append(0)
  74.                 dfs(w,h,set,img)
  75.                 set+=1
  77. #按bbox得到的中心坐标y值对其连通块填充颜色                
  78. def fill(img):
  79.     for w in range(0,width):
  80.         for h in range(0,height):
  81.             if(flag[w][h]>0):
  82.                 num=flag[w][h]-1
  83.                 cy=ymin[num]+(ymax[num]-ymin[num])/2
  84.                 cy=cy/height
  85.                 cy=int(cy*255)
  86.                 img.putpixel((w,h),cy)
  89. if __name__ == '__main__':
  90.     imgPath="D:/testD/F"
  91.     newPath="D:/testD/F_n/"
  92.     files=os.listdir(imgPath)
  93.     for file in files:
  94.         im=Image.open(imgPath+'/'+file)
  95.         width=im.size[0]
  96.         height=im.size[1]
  98.         r,g,b,a=im.split()
  99.         #第一问
  100.         r=r.filter(ImageFilter.GaussianBlur(radius=3))
  101.         g=g.filter(ImageFilter.FIND_EDGES)
  102.         flag=[[0 for j in range(height)] for i in range(width)]
  103.         s=Stack()
  104.         #第二问
  105.         threshold(0.5,g)
  107.         b=g.copy()
  108.         #第三问
  109.         connected(b)
  110.         fill(b)
  111.         img=Image.merge("RGBA",[r,g,b,a])
  112.         img.save(newPath+'/'+file,'png')

给定人物模型制作运动动画并进行物理渲染的线框效果展示。
制作思路:https://www.bilibili.com/read/cv3168157
TIM图片20191025140102.png-64kB

  1. Shader "TestC/wireframe"
  2. {
  3.     Properties
  4.     {
  5.         [Toggle] _NoTriangle("NoTriangle",float)=0
  6.         _wireThickness("wire thickness",Range(0,5))=0.05
  7.         _wireColor("wire color",Color)=(1,1,1,1)
  8.         _wireSmoothing("wire smoothing",Range(0,5))=1
  9.     }
  10.     SubShader
  11.     {
  12.         CGINCLUDE
  13.         #include "UnityCG.cginc"
  14.         #include "Lighting.cginc"
  15.         fixed4 _wireColor;
  16.         half _wireThickness;
  17.         half _wireSmoothing;
  18.         struct a2v{
  19.             float4 vertex:POSITION;
  20.         };
  21.         struct v2g
  22.         {
  23.             float3 vpos:TEXCOORD0;
  24.             float4 wpos : SV_POSITION;
  25.         };
  27.         struct g2f
  28.         {
  29.             float3 vpos:TEXCOORD1;
  30.             float4 pos : SV_POSITION;
  31.             float3 barycentric:TEXCOORD0;
  32.             float3 worldNormal:TEXCOORD2;
  33.         };
  34.         v2g vert (a2v v)
  35.         {
  36.             v2g o;
  37.             o.vpos=v.vertex.xyz;
  38.             o.wpos = mul(unity_ObjectToWorld,v.vertex);
  39.             return o;
  40.         }
  41.         float3 getNormal(float3 pos0, float3 pos1,float3 pos2)
  42.         {
  43.             float3 a=pos1-pos0;
  44.             float b=pos2-pos0;
  45.             return normalize(cross(a,b));
  46.         }
  47.         [maxvertexcount(3)]
  48.         void geom(triangle v2g p[3],inout TriangleStream<g2f> stream)
  49.         {
  50.             g2f o1,o2,o3;
  51.             float3 param=float3(0,0,0);
  52.             #if _NOTRIANGLE_ON
  53.             float EdgeA = length(p[0].vpos - p[1].vpos);
  54.             float EdgeB = length(p[1].vpos - p[2].vpos);
  55.             float EdgeC = length(p[2].vpos - p[0].vpos);
  56.             if(EdgeA > EdgeB && EdgeA > EdgeC)
  57.                 param.y = 1.;
  58.             else if (EdgeB > EdgeC && EdgeB > EdgeA)
  59.                 param.x = 1.;
  60.             else
  61.                 param.z = 1.;
  62.             #endif
  63.             o1.pos=mul(UNITY_MATRIX_VP,p[0].wpos);
  64.             o2.pos=mul(UNITY_MATRIX_VP,p[1].wpos);
  65.             o3.pos=mul(UNITY_MATRIX_VP,p[2].wpos);
  67.             float3 triangleNomral=getNormal(p[0].wpos,p[1].wpos,p[2].wpos);
  68.             o1.worldNormal=triangleNomral;
  69.             o2.worldNormal=triangleNomral;
  70.             o3.worldNormal=triangleNomral;
  72.             o1.barycentric=float3(1,0,0)+param;
  73.             o2.barycentric=float3(0,0,1)+param;
  74.             o3.barycentric=float3(0,1,0)+param;
  76.             o1.vpos=p[0].vpos;
  77.             o2.vpos=p[1].vpos;
  78.             o3.vpos=p[2].vpos;
  80.             stream.Append(o1);
  81.             stream.Append(o2);
  82.             stream.Append(o3);
  83.             stream.RestartStrip();
  84.         }
  85.         inline float aa1 (float threshold, float dist) {
  86.             float delta = fwidth(dist) * _wireSmoothing;
  87.             threshold=threshold*delta;
  88.             return smoothstep(threshold-delta, threshold+delta, dist);
  89.         }
  90.         fixed4 fragfront (g2f i) : SV_Target
  91.         {
  92.             i.worldNormal=normalize(i.worldNormal);
  93.             fixed3 ambient=UNITY_LIGHTMODEL_AMBIENT.xyz;
  94.             fixed3 worldlight_dir=normalize(_WorldSpaceLightPos0.xyz);
  95.             fixed3 diffuse=_LightColor0.rgb*_wireColor.rgb*saturate(dot(normalize(i.worldNormal),worldlight_dir));
  96.             float3 barycentric=float3(i.barycentric.x,i.barycentric.y,i.barycentric.z);
  97.             float thickness=_wireThickness;
  98.             float d=min(barycentric.x,min(barycentric.y,barycentric.z));
  99.             float t=1-aa1(thickness,d);
  100.             return fixed4(ambient+diffuse,t);
  101.         }
  102.         ENDCG
  103.         Pass
  104.         {
  105.             Tags{"Queue"="AlphaTest" "LightMode"="ForwardBase"}
  106.             Cull front
  107.             AlphaToMask On
  108.             CGPROGRAM
  109.             #pragma shader_feature _NOTRIANGLE_ON
  110.             #pragma vertex vert
  111.             #pragma fragment fragfront
  112.             #pragma geometry geom
  113.             #pragma target 4.0
  115.             ENDCG 
  116.         }
  117.         Pass
  118.         {
  119.             Tags{"Queue"="AlphaTest" "LightMode"="ForwardBase"}
  120.             Cull back
  121.             AlphaToMask On
  122.             CGPROGRAM
  123.             #pragma shader_feature _NOTRIANGLE_ON
  124.             #pragma vertex vert
  125.             #pragma fragment fragfront
  126.             #pragma geometry geom
  127.             #pragma target 4.0
  128.             ENDCG
  129.         }
  130.     }
  131.     FallBack "Diffuse"
  132. }
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