我在团结中开始了一个项目，一个滚球游戏。请记住，我是一个新手，所以详细的解释会很有帮助。无论如何，我认为场景看起来不太好，并决定在c#中添加光线追踪脚本。我从这个网站上得到的，http://laht.info/ray-tracing-in-unity/
下面是附在MainCamera 上的代码using UnityEngine;
using System.Collections;
public class RayTracer : MonoBehaviour
{
public Color backgroundColor = Color.black;
public float RenderResolution = 1f;
public float maxDist = 100f;
public int maxRecursion = 4;
private Light[] lights;
private Texture2D renderTexture;
void Awake()
{
renderTexture = new Texture2D((int)(Screen.width * RenderResolution), (int)(Screen.height * RenderResolution));
lights = FindObjectsOfType(typeof(Light)) as Light[];
}
void Start()
{
RayTrace();
}
void OnGUI()
{
GUI.DrawTexture(new Rect(0, 0, Screen.width, Screen.height), renderTexture);
}
void RayTrace()
{
for (int x = 0; x < renderTexture.width; x++)
{
for (int y = 0; y < renderTexture.height; y++)
{
Color color = Color.black;
Ray ray = GetComponent<Camera>().ScreenPointToRay(new Vector3(x / RenderResolution, y / RenderResolution, 0));
renderTexture.SetPixel(x, y, TraceRay(ray, color, 0));
}
}
renderTexture.Apply();
}
Color TraceRay(Ray ray, Color color, int recursiveLevel)
{
if (recursiveLevel < maxRecursion)
{
RaycastHit hit;
if (Physics.Raycast(ray, out hit, maxDist))
{
Vector3 viewVector = ray.direction;
Vector3 pos = hit.point + hit.normal * 0.0001f;
Vector3 normal = hit.normal;
RayTracerObject rto = hit.collider.gameObject.GetComponent<RayTracerObject>();
Material mat = hit.collider.GetComponent<Renderer>().material;
if (mat.mainTexture)
{
color += (mat.mainTexture as Texture2D).GetPixelBilinear(hit.textureCoord.x, hit.textureCoord.y);
}
else
{
color += mat.color;
}
color *= TraceLight(rto, viewVector, pos, normal);
if (rto.reflectiveCoeff > 0)
{
float reflet = 2.0f * Vector3.Dot(viewVector, normal);
Ray newRay = new Ray(pos, viewVector - reflet * normal);
color += rto.reflectiveCoeff * TraceRay(newRay, color, recursiveLevel + 1);
}
if (rto.transparentCoeff > 0)
{
Ray newRay = new Ray(hit.point - hit.normal * 0.0001f, viewVector);
color += rto.transparentCoeff * TraceRay(newRay, color, recursiveLevel + 1);
}
}
}
return color;
}
Color TraceLight(RayTracerObject rto, Vector3 viewVector, Vector3 pos, Vector3 normal)
{
Color c = RenderSettings.ambientLight;
foreach (Light light in lights)
{
if (light.enabled)
{
c += LightTrace(rto, light, viewVector, pos, normal);
}
}
return c;
}
Color LightTrace(RayTracerObject rto, Light light, Vector3 viewVector, Vector3 pos, Vector3 normal)
{
float dot, distance, contribution;
Vector3 direction;
switch (light.type)
{
case LightType.Directional:
contribution = 0;
direction = -light.transform.forward;
dot = Vector3.Dot(direction, normal);
if (dot > 0)
{
if (Physics.Raycast(pos, direction, maxDist))
{
return Color.black;
}
if (rto.lambertCoeff > 0)
{
contribution += dot * rto.lambertCoeff;
}
if (rto.reflectiveCoeff > 0)
{
if (rto.phongCoeff > 0)
{
float reflet = 2.0f * Vector3.Dot(viewVector, normal);
Vector3 phongDir = viewVector - reflet * normal;
float phongTerm = max(Vector3.Dot(phongDir, viewVector), 0.0f);
phongTerm = rto.reflectiveCoeff * Mathf.Pow(phongTerm, rto.phongPower) * rto.phongCoeff;
contribution += phongTerm;
}
if (rto.blinnPhongCoeff > 0)
{
Vector3 blinnDir = -light.transform.forward - viewVector;
float temp = Mathf.Sqrt(Vector3.Dot(blinnDir, blinnDir));
if (temp != 0.0f)
{
blinnDir = (1.0f / temp) * blinnDir;
float blinnTerm = max(Vector3.Dot(blinnDir, normal), 0.0f);
blinnTerm = rto.reflectiveCoeff * Mathf.Pow(blinnTerm, rto.blinnPhongPower) * rto.blinnPhongCoeff;
contribution += blinnTerm;
}
}
}
}
return light.color * light.intensity * contribution;
case LightType.Point:
contribution = 0;
direction = (light.transform.position - pos).normalized;
dot = Vector3.Dot(normal, direction);
distance = Vector3.Distance(pos, light.transform.position);
if ((distance < light.range) && (dot > 0))
{
if (Physics.Raycast(pos, direction, distance))
{
return Color.black;
}
if (rto.lambertCoeff > 0)
{
contribution += dot * rto.lambertCoeff;
}
if (rto.reflectiveCoeff > 0)
{
if (rto.phongCoeff > 0)
{
float reflet = 2.0f * Vector3.Dot(viewVector, normal);
Vector3 phongDir = viewVector - reflet * normal;
float phongTerm = max(Vector3.Dot(phongDir, viewVector), 0.0f);
phongTerm = rto.reflectiveCoeff * Mathf.Pow(phongTerm, rto.phongPower) * rto.phongCoeff;
contribution += phongTerm;
}
if (rto.blinnPhongCoeff > 0)
{
Vector3 blinnDir = -light.transform.forward - viewVector;
float temp = Mathf.Sqrt(Vector3.Dot(blinnDir, blinnDir));
if (temp != 0.0f)
{
blinnDir = (1.0f / temp) * blinnDir;
float blinnTerm = max(Vector3.Dot(blinnDir, normal), 0.0f);
blinnTerm = rto.reflectiveCoeff * Mathf.Pow(blinnTerm, rto.blinnPhongPower) * rto.blinnPhongCoeff;
contribution += blinnTerm;
}
}
}
}
if (contribution == 0)
{
return Color.black;
}
return light.color * light.intensity * contribution;
case LightType.Spot:
contribution = 0;
direction = (light.transform.position - pos).normalized;
dot = Vector3.Dot(normal, direction);
distance = Vector3.Distance(pos, light.transform.position);
if (distance < light.range && dot > 0)
{
float dot2 = Vector3.Dot(-light.transform.forward, direction);
if (dot2 > (1 - light.spotAngle / 180))
{
if (Physics.Raycast(pos, direction, distance))
{
return Color.black;
}
if (rto.lambertCoeff > 0)
{
contribution += dot * rto.lambertCoeff;
}
if (rto.reflectiveCoeff > 0)
{
if (rto.phongCoeff > 0)
{
float reflet = 2.0f * Vector3.Dot(viewVector, normal);
Vector3 phongDir = viewVector - reflet * normal;
float phongTerm = max(Vector3.Dot(phongDir, viewVector), 0.0f);
phongTerm = rto.reflectiveCoeff * Mathf.Pow(phongTerm, rto.phongPower) * rto.phongCoeff;
contribution += phongTerm;
}
if (rto.blinnPhongCoeff > 0)
{
Vector3 blinnDir = -light.transform.forward - viewVector;
float temp = Mathf.Sqrt(Vector3.Dot(blinnDir, blinnDir));
if (temp != 0.0f)
{
blinnDir = (1.0f / temp) * blinnDir;
float blinnTerm = max(Vector3.Dot(blinnDir, normal), 0.0f);
blinnTerm = rto.reflectiveCoeff * Mathf.Pow(blinnTerm, rto.blinnPhongPower) * rto.blinnPhongCoeff;
contribution += blinnTerm;
}
}
}
}
}
if (contribution == 0)
{
return Color.black;
}
return light.color * light.intensity * contribution;
}
return Color.black;
}
float max(float x0, float x1)
{
return x0 > x1 ? x0 : x1;
}
}
这是附属于场景中物体的代码，比如平面或球体
using UnityEngine;
using System.Collections;
public class RayTracerObject : MonoBehaviour
{
public float lambertCoeff = 1f;
public float reflectiveCoeff = 0f;
public float phongCoeff = 1f;
public float phongPower = 2f;
public float blinnPhongCoeff = 1f;
public float blinnPhongPower = 2f;
public float transparentCoeff = 0f;
public Color baseColor = Color.gray;
void Awake()
{
if (!GetComponent<Renderer>().material.mainTexture)
{
GetComponent<Renderer>().material.color = baseColor;
}
}
}
无论如何，当我尝试运行程序时，我得到了这个错误。
NullReferenceException:对象引用未设置为对象的实例光线跟踪。LightTrace(。RayTracerObject rto, UnityEngine。光，Vector3 viewVector, Vector3 pos, Vector3 normal)(在Assets/Scripts/RayTracer.cs:127)光线跟踪。TraceLight(。RayTracerObject rto, Vector3 viewVector, Vector3 pos, Vector3 normal)(在Assets/Scripts/RayTracerObject .cs:102)光线跟踪。TraceRay (Ray Ray, Color Color, Int32 recursivellevel)(在Assets/Scripts/RayTracer.cs:73)光线跟踪。RayTrace () (at Assets/Scripts/RayTrace .cs:42)
如果你能弄清楚这一点，发布代码会有很大帮助。谢谢你！
张贴发生错误的行将会很有帮助。无论如何，第127行是LightTrace()函数中的这一行。
if (rto.lambertCoeff > 0)
{
contribution += dot * rto.lambertCoeff;
}
因此，rto变量必须为空。我不知道为什么是空的，虽然。LightTrace()函数只能从这里调用:
Color TraceLight(RayTracerObject rto, Vector3 viewVector, Vector3 pos, Vector3 normal)
{
Color c = RenderSettings.ambientLight;
foreach (Light light in lights)
{
if (light.enabled)
{
c += LightTrace(rto, light, viewVector, pos, normal);
}
}
return c;
}
那么TraceLight函数从哪里获得rto对象呢?从这里:(这是在TraceRay函数内)
RayTracerObject rto = hit.collider.gameObject.GetComponent<RayTracerObject>();
Material mat = hit.collider.GetComponent<Renderer>().material;
if (mat.mainTexture)
{
color += (mat.mainTexture as Texture2D).GetPixelBilinear(hit.textureCoord.x, hit.textureCoord.y);
}
else
{
color += mat.color;
}
color *= TraceLight(rto, viewVector, pos, normal);
这里我们可以看到，没有检查GetComponent<RayTracerObject>()调用是否返回实际的RayTracerObject脚本，而不是null。也许他们希望场景中的每个物体都有这个脚本。无论如何，在对rto变量赋值后放置一个!= null检查，这样就可以了。另外，你还可以继续调试它，比如Debug.Log()，看看它到底碰到了哪个没有RayTracerObject的对象。
编辑:所以，你应该开始调试你的场景，看看什么Physics.Raycast()命中没有RayTracerObject脚本。当使用该脚本时，你应该确保绝对每个对象，它可以用光线投射击中，有RayTracerObject脚本。在TraceRay()函数中，添加一些调试
Color TraceRay(Ray ray, Color color, int recursiveLevel)
{
if (recursiveLevel < maxRecursion)
{
RaycastHit hit;
if (Physics.Raycast(ray, out hit, maxDist))
{
Vector3 viewVector = ray.direction;
Vector3 pos = hit.point + hit.normal * 0.0001f;
Vector3 normal = hit.normal;
RayTracerObject rto = hit.collider.gameObject.GetComponent<RayTracerObject>();
//Does the object we hit have that script?
if(rto == null)
{
var GO = hit.collider.gameObject;
Debug.Log("Raycast hit failure! On " + GO.name + " position " + GO.transform.position.ToString());
return color; //exit out
}
快乐调试。