扇形技能指示器
网上基本有两种方法写扇形指示器：
- 生成Mesh拼接
- Shader绘制
Mesh拼接
我这边用Unity自带的Gizmos简单的绘制一下Mesh
注意：Gizmos.DrawMesh()中的Mesh必须包含vertices和normals
生成vertices
///
/// 生成vertices
///
/// 三角形数量
/// 原点
/// 朝向
/// vertuces
private Vector3[] GetVectors(int precision, Vector3 originPos, Vector3 forward)
{
// 一共需要三角形数量+2的顶点数
Vector3[] meshVectors = new Vector3[precision + 2];
// 每个三角形的角度
float meshRadius = angle / precision;
// 起始三角形朝向
forward = Quaternion.AngleAxis(-angle / 2, Vector3.up) * forward;
// 特殊设置0与1的顶点位置
meshVectors[0] = originPos;
meshVectors[1] = originPos + forward * radius;
// 后续定点按规律生成
for (int i = 2; i < precision + 2; i++)
{
// 旋转一个三角形的朝向
forward = Quaternion.AngleAxis(meshRadius, Vector3.up) * forward;
// 设置定点
meshVectors[i] = originPos + forward * radius;
}
return meshVectors;
}生成Triangles
///
/// 生成triangles
///
/// 三角形数量
/// triangles
private int[] GetTriangles(int precision)
{
// 每个三角形三个triangle
int[] meshTriangles = new int[precision * 3];
// 按规律生成
for (int i = 0; i < precision; i++)
{
int id = i * 3;
meshTriangles[id] = 0;
meshTriangles[id + 1] = i + 1;
meshTriangles[id + 2] = i + 2;
}
return meshTriangles;
}利用OnDrawGizmos绘制三角形
public float angle; // 角度
public float radius; // 半径
public int precision; // 三角形数量（越多约成圆，效率越低）
public GameObject origin; // 原点GameObject（表示原点位置用）
private void OnDrawGizmos()
{
Mesh mesh = new Mesh();
mesh.vertices = GetVectors(precision, origin.transform.position, origin.transform.forward);
mesh.triangles = GetTriangles(precision);
// 生成normals
mesh.RecalculateNormals();
Gizmos.color = Color.red;
// 画线框（Mesh会挡住线框的绘制）
for (int i = 1; i < mesh.vertices.Length; i++)
{
Gizmos.DrawLine(mesh.vertices[0], mesh.vertices[i]);
Gizmos.DrawLine(mesh.vertices[i], mesh.vertices[i - 1]);
}
// 画Mesh
Gizmos.DrawMesh(mesh);
}Shader绘制
属性
_Inner ("Inner Texture", 2D) = "white" {} // 内圈贴图
_Outer ("Outer Texture", 2D) = "white" {} // 外圈贴图
_Color ("Color", Color) = (1, 1, 1, 1) // 颜色
_Angle ("Angle", Range(0, 360)) = 60 // 角度
_OutLine ("Out Line", Range(0, 1)) = 0.1 // 外圈宽度核心剔除代码
fixed4 frag(fragmentInput i) : SV_Target
{
// 距离超过半径则剔除
float distance = pow(i.uv.x - 0.5, 2) + pow(i.uv.y - 0.5, 2);
if (distance > 0.25f) {
discard;
}
float x = i.uv.x;
float y = i.uv.y;
float deg2rad = 0.017453; // 角度转弧度
if (_Angle > 180) {
if(y > 0.5 && abs(0.5 - y) >= abs(0.5 - x) / tan((180 - _Angle / 2) * deg2rad)) {
discard;
}
else {
if(y > 0.5 || abs(0.5 -y) < abs(0.5 - x) / tan(_Angle / 2 * deg2rad)) {
discard;
}
}
// 外圈显示比例
float outDis = 0.25 * pow((1 - _OutLine), 2);
if (distance > outDis) {
// 外圈绘制
return tex2D(_Outer, i.uv) * _Color;
}
else {
// 内圈绘制
return tex2D(_Inner, i.uv) * _Color;
}
}Shader "Unlit/SectorShader"
{
Properties {
_Inner ("Inner Texture", 2D) = "white" {}
_Outer ("Outer Texture", 2D) = "white" {}
_Color ("Color", Color) = (1, 1, 1, 1)
_Angle ("Angle", Range(0, 360)) = 60
_OutLine ("Out Line", Range(0, 1)) = 0.1
}
SubShader {
Tags { "Queue"="Transparent" "RenderType"="Transparent" "IgnoreProjector"="True" }
Pass {
ZWrite Off
Blend SrcAlpha OneMinusSrcAlpha
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
sampler2D _Inner;
sampler2D _Outer;
float4 _Color;
float _Angle;
float _OutLine;
struct fragmentInput
{
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
};
fragmentInput vert (appdata_base v)
{
fragmentInput o;
o.pos = UnityObjectToClipPos (v.vertex);
o.uv = v.texcoord.xy;
return o;
}
fixed4 frag(fragmentInput i) : SV_Target
{
float distance = pow(i.uv.x - 0.5, 2) + pow(i.uv.y - 0.5, 2);
if (distance > 0.25f)
{
discard;
}
float x = i.uv.x;
float y = i.uv.y;
float deg2rad = 0.017453; // 角度转弧度
if (_Angle > 180)
{
if(y > 0.5 && abs(0.5 - y) >= abs(0.5 - x) / tan((180 - _Angle / 2) * deg2rad))
{
discard;
}
}
else
{
if(y > 0.5 || abs(0.5 -y) < abs(0.5 - x) / tan(_Angle / 2 * deg2rad))
{
discard;
}
}
float outDis = 0.25 * pow((1 - _OutLine), 2);
if (distance > outDis)
{
return tex2D(_Outer, i.uv) * _Color;
}
else
{
return tex2D(_Inner, i.uv) * _Color;
}
}
ENDCG
}
}
FallBack "Diffuse"
}