Unity Shader 如何实现火焰特效
发表于2018-06-13
为了让游戏中的角色技能更加多样化，有时候会给角色加一些火焰特效，下面就用给大家分享下shader实现火焰特效的方法。
效果图如下：
火焰效果制作方法
1、C#部分的代码如下：
using UnityEngine;
using System.Collections;
[ExecuteInEditMode]
public class CamRendImage : MonoBehaviour ｛
[SerializeField]
private Material m_mat;
// Use this for initialization
void Start () ｛
｝
// Update is called once per frame
void Update () ｛
｝
void OnRenderImage(RenderTexture src,RenderTexture dest)
｛
Graphics.Blit (src,dest,m_mat);
｝
void OnMouseDown()
｛
｝
void OnMouseUp()
｛
｝
2、Shader代码如下：
Shader "Unlit/Flame"
｛
Properties｛
｝
CGINCLUDE
#include "UnityCG.cginc"
#pragma target 3.0
#define vec2 float2
#define vec3 float3
#define vec4 float4
#define mat2 float2x2
#define mat3 float3x3
#define mat4 float4x4
#define iGlobalTime _Time.y
#define mod fmod
#define mix lerp
#define fract frac
#define texture2D tex2D
#define iResolution _ScreenParams
#define gl_FragCoord ((_iParam.scrPos.xy/_iParam.scrPos.w) * _ScreenParams.xy)
#define PI2 6.28318530718
#define pi 3.14159265358979
#define halfpi (pi * 0.5)
#define oneoverpi (1.0 / pi)
vec4 main(in vec2 fragCoord );
struct v2f ｛
float4 pos : SV_POSITION;
float4 scrPos : TEXCOORD0;
｝;
v2f vert(appdata_base v) ｛
v2f o;
o.pos = mul (UNITY_MATRIX_MVP, v.vertex);
o.scrPos = ComputeScreenPos(o.pos);
return o;
｝
fixed4 frag(v2f _iParam) : COLOR0 ｛
vec2 fragCoord = gl_FragCoord;
return main(gl_FragCoord);
｝
float noise(vec3 p) //Thx to Las^Mercury
｛
vec3 i = floor(p);
vec4 a = dot(i, vec3(1., 57., 21.)) + vec4(0., 57., 21., 78.);
vec3 f = cos((p-i)*acos(-1.))*(-.5)+.5;
a = mix(sin(cos(a)*a),sin(cos(1.+a)*(1.+a)), f.x);
a.xy = mix(a.xz, a.yw, f.y);
return mix(a.x, a.y, f.z);
｝
float sphere(vec3 p, vec4 spr)
｛
return length(spr.xyz-p) - spr.w;
｝
float flame(vec3 p)
｛
float d = sphere(p*vec3(1.,.5,1.), vec4(.0,-1.,.0,1.));
return d + (noise(p+vec3(.0,iGlobalTime*2.,.0)) + noise(p*3.)*.5)*.25*(p.y) ;
｝
float scene(vec3 p)
｛
return min(100.-length(p) , abs(flame(p)) );
｝
vec4 raymarch(vec3 org, vec3 dir)
｛
float d = 0.0, glow = 0.0, eps = 0.02;
vec3 p = org;
bool glowed = false;
for(int i=0; i<64; i++)
｛
d = scene(p) + eps;
p += d * dir;
if( d>eps )
｛
if(flame(p) < .0)
glowed=true;
if(glowed)
glow = float(i)/64.;
｝
｝
return vec4(p,glow);
｝
vec4 main(in vec2 fragCoord )
｛
vec4 fragColor;
vec2 v = -1.0 + 2.0 * fragCoord.xy / iResolution.xy;
v.x *= iResolution.x/iResolution.y;
vec3 org = vec3(0., -2., 4.);
vec3 dir = normalize(vec3(v.x*1.6, -v.y, -1.5));
vec4 p = raymarch(org, dir);
float glow = p.w;
vec4 col = mix(vec4(1.0,0.5,0.1,1.0), vec4(0.1,0.5,1.0,1.0), p.y*0.02+0.4);
fragColor = mix(vec4(0,0,0,0), col, pow(glow*2.,4.));
//fragColor = mix(vec4(1.), mix(vec4(1.,.5,.1,1.),vec4(0.1,.5,1.,1.),p.y*.02+.4), pow(glow*2.,4.));
return fragColor;
｝
ENDCG
SubShader ｛
Pass ｛
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest
ENDCG
｝
｝
FallBack Off
｝
将1中的C#脚本赋给主摄像机，然后将附有2中的Shader的材质赋值给C#脚本中的“m_mat”变量。