Files
Emberwild/Assets/URPWater/Scripts/URPWaterReflection.cs
T
2026-06-22 16:18:34 +02:00

299 lines
11 KiB
C#

using UnityEngine;
using System;
using UnityEngine.Rendering.Universal;
using UnityEngine.Rendering;
using UnityEngine.Experimental.Rendering;
namespace URPWater
{
[ExecuteAlways]
public class URPWaterReflection : MonoBehaviour
{
[Serializable]
public enum Quality
{
VeryHigh,
High,
Medium,
Low
}
[SerializeField]
private Quality _Quality = Quality.High;
[SerializeField]
private float _ClipPlaneOffset = 0.07f;
[SerializeField]
private float _PlaneOffset = 0f;
[SerializeField]
private LayerMask _LayerMask = -1;
[SerializeField]
private bool _Shadows = false;
public GameObject target;
private static Camera _ReflectionCamera;
private RenderTexture _ReflectionTexture;
private readonly int _ReflectionTextureId = Shader.PropertyToID("_ReflectionTexture");
public static event Action<ScriptableRenderContext, Camera> BeginReflections;
private void OnEnable()
{
RenderPipelineManager.beginCameraRendering += ComputeReflections;
}
// Cleanup all the objects we possibly have created
private void OnDisable()
{
Cleanup();
}
private void OnDestroy()
{
Cleanup();
}
private void ComputeReflections(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;
// For overlay Camera
var cameraData = camera.GetUniversalAdditionalCameraData();
if (cameraData.renderType != CameraRenderType.Base)
return;
if(cameraData.transform.eulerAngles == Vector3.zero)
{
return;
}
UpdateReflectionCamera(camera); // create reflected camera
PlanarReflectionTexture(camera); // create and assign RenderTexture
var data = new ReflectionSettingData(); // save quality settings and lower them for the planar reflections
data.Set(); // set quality settings
BeginReflections?.Invoke(context, _ReflectionCamera); // callback Action for PlanarReflection
#pragma warning disable CS0618
UniversalRenderPipeline.RenderSingleCamera(context, _ReflectionCamera); // render planar reflections
#pragma warning restore CS0618
data.Restore(); // restore the quality settings
Shader.SetGlobalTexture(_ReflectionTextureId, _ReflectionTexture); // Assign texture to water shader
}
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 = _Shadows; // turn off shadows for the reflection camera
}
}
private void UpdateReflectionCamera(Camera realCamera)
{
if (_ReflectionCamera == null)
_ReflectionCamera = CreateReflectionCamera();
// find out the reflection plane: position and normal in world space
Vector3 pos = transform.position;
Vector3 normal = Vector3.up;
if (target != null)
{
pos = target.transform.position + Vector3.up * _PlaneOffset;
normal = target.transform.up;
}
UpdateCamera(realCamera, _ReflectionCamera);
// Render reflection
// Reflect camera around reflection plane
var d = -Vector3.Dot(normal, pos) - _ClipPlaneOffset;
var reflectionPlane = new Vector4(normal.x, normal.y, normal.z, d);
var reflection = Matrix4x4.identity;
reflection *= Matrix4x4.Scale(new Vector3(1, -1, 1));
ReflectionMatrix(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 = _LayerMask & ~(1 << LayerMask.NameToLayer("Water"));// never render water layer
_ReflectionCamera.transform.position = newPosition;
}
private void Cleanup()
{
RenderPipelineManager.beginCameraRendering -= ComputeReflections;
if (_ReflectionCamera)
{
_ReflectionCamera.targetTexture = null;
SafeDestroy(_ReflectionCamera.gameObject);
}
if (_ReflectionTexture)
{
RenderTexture.ReleaseTemporary(_ReflectionTexture);
}
}
private static void SafeDestroy(UnityEngine.Object obj)
{
if (Application.isEditor)
{
DestroyImmediate(obj);
}
else
{
Destroy(obj);
}
}
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((int)res.x, (int)res.y, 16,
GraphicsFormatUtility.GetGraphicsFormat(hdrFormat, true));
_ReflectionTexture.useMipMap = true;
_ReflectionTexture.autoGenerateMips = true;
}
_ReflectionCamera.targetTexture = _ReflectionTexture;
}
private Vector2 ReflectionResolution(Camera cam, float scale)
{
var x = (int)(cam.pixelWidth * scale * GetScaleValue());
var y = (int)(cam.pixelHeight * scale * GetScaleValue());
return new Vector2(x, y);
}
private float GetScaleValue()
{
switch (_Quality)
{
case Quality.VeryHigh:
return 1f;
case Quality.High:
return 0.5f;
case Quality.Medium:
return 0.33f;
case Quality.Low:
return 0.25f;
default:
return 0.5f;
}
}
private Camera CreateReflectionCamera()
{
var go = new GameObject("Reflection Camera", typeof(Camera));
var cameraData = go.AddComponent(typeof(UniversalAdditionalCameraData)) as UniversalAdditionalCameraData;
cameraData.requiresColorOption = CameraOverrideOption.Off;
cameraData.requiresDepthOption = CameraOverrideOption.Off;
cameraData.SetRenderer(0);
var t = transform;
var reflectionCamera = go.GetComponent<Camera>();
reflectionCamera.transform.SetPositionAndRotation(t.position, t.rotation);
reflectionCamera.depth = -10;
reflectionCamera.enabled = false;
reflectionCamera.nearClipPlane = 1.0f;
go.hideFlags = HideFlags.HideAndDontSave;
return reflectionCamera;
}
// Calculates reflection matrix around the given plane
private static void ReflectionMatrix(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;
}
// 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 * _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 static Vector3 ReflectPosition(Vector3 pos)
{
var newPos = new Vector3(pos.x, -pos.y, pos.z);
return newPos;
}
class ReflectionSettingData
{
private readonly bool _Fog;
private readonly int _MaxLod;
private readonly float _LodBias;
public ReflectionSettingData()
{
_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;
}
}
}
}