Unity3d Mesh (v) Draw the Circle

Objective:

The basic unit of mesh in Unity3d is a triangle, and the circle is made up of many triangles. Then we'll know. It takes two variables to draw a circular mesh: the radius of the circle and the number of splits;

First, the realization process

The basic process is similar to the previous one, the most basic is still the vertex and triangle index array, namely: we need to according to the radius of the circle and the number of pre-divided , through the algorithm to obtain: Vertex Vector3 array and corresponding triangle index array;

1, the Basic Program implementation Framework is as follows:

usingUnityengine; [Requirecomponent (typeof(Meshrenderer),typeof(Meshfilter))] Public classyuan:monobehaviour{ Public floatRadius =6;//radius     Public intsegments = -;//Split number    PrivateMeshfilter Meshfilter; voidStart () {Meshfilter= getcomponent<meshfilter>(); Meshfilter.mesh=Createmesh (Radius, segments); } Mesh Createmesh (floatRadiusintsegments) {Mesh Mesh=NewMesh (); returnmesh; }}

2, next need to implement the basic functions of the Createmesh () function (the following program contains the function of the implementation of the functions); The code for the entire program is as follows:

usingUnityengine; [Requirecomponent (typeof(Meshrenderer),typeof(Meshfilter))] Public classyuan:monobehaviour{ Public floatRadius =6;//radius     Public intsegments = -;//Split number    PrivateMeshfilter Meshfilter; voidStart () {Meshfilter= getcomponent<meshfilter>(); Meshfilter.mesh=Createmesh (Radius, segments); } Mesh Createmesh (floatRadiusintsegments) {        //vertices:        intVertices_count = segments +1; Vector3[] vertices=NewVector3[vertices_count]; vertices[0] =Vector3.zero; floatAngledegree =360.0f; floatAnglerad = Mathf.deg2rad *Angledegree; floatAnglecur =Anglerad; floatAngledelta = Anglerad/segments;  for(intI=1;i< Vertices_count; i++)        {            floatCosA =Mathf.cos (anglecur); floatSinA =Mathf.sin (anglecur); Vertices[i]=NewVector3 (Radius * CosA,0, Radius *SinA); Anglecur-=Angledelta; }        //Triangles        intTriangle_count = segments *3; int[] Triangles =New int[Triangle_count];  for(intI=0, vi=1; i<= triangle_count-1; i+=3, vi++)//because the case splits 60 triangles, the last index order should be: 0 60 1; So it needs to be handled separately.{Triangles[i]=0; Triangles[i+1] =VI; Triangles[i+2] = VI +1; } Triangles[triangle_count-3] =0; Triangles[triangle_count-2] = Vertices_count-1; Triangles[triangle_count-1] =1;//to complete the closed loop, lift the last triangle alone.//UV:vector2[] Uvs =NewVector2[vertices_count];  for(inti =0; i < Vertices_count; i++) {Uvs[i]=NewVector2 (Vertices[i].x/radius/2+0.5f, Vertices[i].z/radius/2+0.5f); }        //load properties and meshMesh mesh =NewMesh (); Mesh.vertices=vertices; Mesh.triangles=triangles; Mesh.uv=Uvs; returnmesh; }}

3.:

Little knowledge of the encounter:

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Unity3d Mesh (v) Draw the Circle