Unity Chan 工程分享 - URP渲染实现 Unity版本:2019.4
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using System;
using UnityEngine.Experimental.Rendering;
using UnityEngine.Serialization;
using Unity.Mathematics;
namespace UnityEngine.Rendering.Universal
{
[ExecuteAlways]
public class PlanarReflections : MonoBehaviour
{
[Serializable]
public enum ResolutionMulltiplier
{
Full,
Half,
Third,
Quarter
}
[Serializable]
public class PlanarReflectionSettings
{
public ResolutionMulltiplier m_ResolutionMultiplier = ResolutionMulltiplier.Third;
public float m_ClipPlaneOffset = 0.07f;
public LayerMask m_ReflectLayers = -1;
public bool m_Shadows;
}
[SerializeField]
public PlanarReflectionSettings m_settings = new PlanarReflectionSettings();
public GameObject target;
[FormerlySerializedAs("camOffset")] public float m_planeOffset;
private static Camera _reflectionCamera;
private RenderTexture _reflectionTexture;
private readonly int _planarReflectionTextureId = Shader.PropertyToID("_PlanarReflectionTexture");
private int2 _oldReflectionTextureSize;
public static event Action<ScriptableRenderContext, Camera> BeginPlanarReflections;
private void OnEnable()
{
RenderPipelineManager.beginCameraRendering += ExecutePlanarReflections;
}
// Cleanup all the objects we possibly have created
private void OnDisable()
{
Cleanup();
}
private void OnDestroy()
{
Cleanup();
}
private void Cleanup()
{
RenderPipelineManager.beginCameraRendering -= ExecutePlanarReflections;
if(_reflectionCamera)
{
_reflectionCamera.targetTexture = null;
SafeDestroy(_reflectionCamera.gameObject);
}
if (_reflectionTexture)
{
RenderTexture.ReleaseTemporary(_reflectionTexture);
}
}
private static void SafeDestroy(Object obj)
{
if (Application.isEditor)
{
DestroyImmediate(obj);
}
else
{
Destroy(obj);
}
}
private void UpdateCamera(Camera src, Camera dest)
{
if (dest == null) return;
dest.CopyFrom(src);
dest.useOcclusionCulling = false;
if (dest.gameObject.TryGetComponent(out UniversalAdditionalCameraData camData))
{
camData.renderShadows = m_settings.m_Shadows; // turn off shadows for the reflection camera
}
}
private void UpdateReflectionCamera(Camera realCamera)
{
if (_reflectionCamera == null)
_reflectionCamera = CreateMirrorObjects();
// find out the reflection plane: position and normal in world space
Vector3 pos = Vector3.zero;
Vector3 normal = Vector3.up;
if (target != null)
{
pos = target.transform.position + Vector3.up * m_planeOffset;
normal = target.transform.up;
}
UpdateCamera(realCamera, _reflectionCamera);
// Render reflection
// Reflect camera around reflection plane
var d = -Vector3.Dot(normal, pos) - m_settings.m_ClipPlaneOffset;
var reflectionPlane = new Vector4(normal.x, normal.y, normal.z, d);
var reflection = Matrix4x4.identity;
reflection *= Matrix4x4.Scale(new Vector3(1, -1, 1));
CalculateReflectionMatrix(ref reflection, reflectionPlane);
var oldPosition = realCamera.transform.position - new Vector3(0, pos.y * 2, 0);
var newPosition = ReflectPosition(oldPosition);
_reflectionCamera.transform.forward = Vector3.Scale(realCamera.transform.forward, new Vector3(1, -1, 1));
_reflectionCamera.worldToCameraMatrix = realCamera.worldToCameraMatrix * reflection;
// Setup oblique projection matrix so that near plane is our reflection
// plane. This way we clip everything below/above it for free.
var clipPlane = CameraSpacePlane(_reflectionCamera, pos - Vector3.up * 0.1f, normal, 1.0f);
var projection = realCamera.CalculateObliqueMatrix(clipPlane);
_reflectionCamera.projectionMatrix = projection;
_reflectionCamera.cullingMask = m_settings.m_ReflectLayers; // never render water layer
_reflectionCamera.transform.position = newPosition;
}
// Calculates reflection matrix around the given plane
private static void CalculateReflectionMatrix(ref Matrix4x4 reflectionMat, Vector4 plane)
{
reflectionMat.m00 = (1F - 2F * plane[0] * plane[0]);
reflectionMat.m01 = (-2F * plane[0] * plane[1]);
reflectionMat.m02 = (-2F * plane[0] * plane[2]);
reflectionMat.m03 = (-2F * plane[3] * plane[0]);
reflectionMat.m10 = (-2F * plane[1] * plane[0]);
reflectionMat.m11 = (1F - 2F * plane[1] * plane[1]);
reflectionMat.m12 = (-2F * plane[1] * plane[2]);
reflectionMat.m13 = (-2F * plane[3] * plane[1]);
reflectionMat.m20 = (-2F * plane[2] * plane[0]);
reflectionMat.m21 = (-2F * plane[2] * plane[1]);
reflectionMat.m22 = (1F - 2F * plane[2] * plane[2]);
reflectionMat.m23 = (-2F * plane[3] * plane[2]);
reflectionMat.m30 = 0F;
reflectionMat.m31 = 0F;
reflectionMat.m32 = 0F;
reflectionMat.m33 = 1F;
}
private static Vector3 ReflectPosition(Vector3 pos)
{
var newPos = new Vector3(pos.x, -pos.y, pos.z);
return newPos;
}
private float GetScaleValue()
{
switch(m_settings.m_ResolutionMultiplier)
{
case ResolutionMulltiplier.Full:
return 1f;
case ResolutionMulltiplier.Half:
return 0.5f;
case ResolutionMulltiplier.Third:
return 0.33f;
case ResolutionMulltiplier.Quarter:
return 0.25f;
default:
return 0.5f; // default to half res
}
}
// Compare two int2
private static bool Int2Compare(int2 a, int2 b)
{
return a.x == b.x && a.y == b.y;
}
// Given position/normal of the plane, calculates plane in camera space.
private Vector4 CameraSpacePlane(Camera cam, Vector3 pos, Vector3 normal, float sideSign)
{
var offsetPos = pos + normal * m_settings.m_ClipPlaneOffset;
var m = cam.worldToCameraMatrix;
var cameraPosition = m.MultiplyPoint(offsetPos);
var cameraNormal = m.MultiplyVector(normal).normalized * sideSign;
return new Vector4(cameraNormal.x, cameraNormal.y, cameraNormal.z, -Vector3.Dot(cameraPosition, cameraNormal));
}
private Camera CreateMirrorObjects()
{
var go = new GameObject("Planar Reflections",typeof(Camera));
var cameraData = go.AddComponent(typeof(UniversalAdditionalCameraData)) as UniversalAdditionalCameraData;
cameraData.requiresColorOption = CameraOverrideOption.Off;
cameraData.requiresDepthOption = CameraOverrideOption.Off;
cameraData.SetRenderer(1);
var t = transform;
var reflectionCamera = go.GetComponent<Camera>();
reflectionCamera.transform.SetPositionAndRotation(t.position, t.rotation);
reflectionCamera.depth = -10;
reflectionCamera.enabled = false;
go.hideFlags = HideFlags.HideAndDontSave;
return reflectionCamera;
}
private void PlanarReflectionTexture(Camera cam)
{
if (_reflectionTexture == null)
{
var res = ReflectionResolution(cam, UniversalRenderPipeline.asset.renderScale);
const bool useHdr10 = true;
const RenderTextureFormat hdrFormat = useHdr10 ? RenderTextureFormat.RGB111110Float : RenderTextureFormat.DefaultHDR;
_reflectionTexture = RenderTexture.GetTemporary(res.x, res.y, 16,
GraphicsFormatUtility.GetGraphicsFormat(hdrFormat, true));
}
_reflectionCamera.targetTexture = _reflectionTexture;
}
private int2 ReflectionResolution(Camera cam, float scale)
{
var x = (int)(cam.pixelWidth * scale * GetScaleValue());
var y = (int)(cam.pixelHeight * scale * GetScaleValue());
return new int2(x, y);
}
private void ExecutePlanarReflections(ScriptableRenderContext context, Camera camera)
{
// we dont want to render planar reflections in reflections or previews
if (camera.cameraType == CameraType.Reflection || camera.cameraType == CameraType.Preview)
return;
UpdateReflectionCamera(camera); // create reflected camera
PlanarReflectionTexture(camera); // create and assign RenderTexture
var data = new PlanarReflectionSettingData(); // save quality settings and lower them for the planar reflections
data.Set(); // set quality settings
BeginPlanarReflections?.Invoke(context, _reflectionCamera); // callback Action for PlanarReflection
UniversalRenderPipeline.RenderSingleCamera(context, _reflectionCamera); // render planar reflections
data.Restore(); // restore the quality settings
Shader.SetGlobalTexture(_planarReflectionTextureId, _reflectionTexture); // Assign texture to water shader
}
class PlanarReflectionSettingData
{
private readonly bool _fog;
private readonly int _maxLod;
private readonly float _lodBias;
public PlanarReflectionSettingData()
{
_fog = RenderSettings.fog;
_maxLod = QualitySettings.maximumLODLevel;
_lodBias = QualitySettings.lodBias;
}
public void Set()
{
GL.invertCulling = true;
RenderSettings.fog = false; // disable fog for now as it's incorrect with projection
QualitySettings.maximumLODLevel = 1;
QualitySettings.lodBias = _lodBias * 0.5f;
}
public void Restore()
{
GL.invertCulling = false;
RenderSettings.fog = _fog;
QualitySettings.maximumLODLevel = _maxLod;
QualitySettings.lodBias = _lodBias;
}
}
}
}