Hi All,
I have been working on a project for generating pixel perfect sharp shadows. I am generating shadow volumes, and using a custom render feature in URP11 to inject the volumes into the _ScreenSpaceShadowmapTexture.
It works swimmingly, and I am able to get it to render fine in the game view.
The problem lies here:
When I blit the texture into the existing _ScreenSpaceShadowmapTexture, I use a custom blit shader that flips the y coordinate like this.
if (_ProjectionParams.x < 0)
o.texcoord.y = 1 - o.texcoord.y;
This works out great in the game view, but it flips the texture in the scene view.
I know this is not the biggest problem, but it is quite annoying, and I would like to fix it.
Here is my render pass code for reference:
Render Pass
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;
namespace StencilShadowGenerator.Core.RenderFeature
{
class ShadowVolumeRenderPass : ScriptableRenderPass
{
private readonly Material _occluderMaterial;
private readonly Material _shadowMaterial;
private readonly Material _blitMaterial;
private readonly ShaderTagId _volumeShader;
private readonly List<ShaderTagId> _occluderShaders;
private RenderTargetIdentifier _shadowMap;
private RenderTargetHandle _tempTarget;
private ShadowVolumeRenderingSettings _settings;
private FilteringSettings _filteringSettings;
public ShadowVolumeRenderPass(ShadowVolumeRenderingSettings settings)
{
_settings = settings;
// set up render textures
_tempTarget = RenderTargetHandle.CameraTarget;
_shadowMap = new RenderTargetIdentifier(Shader.PropertyToID("_ScreenSpaceShadowmapTexture"));
// set up materials
_occluderMaterial = new Material(Shader.Find("Hidden/ShadowVolumes/White"));
_shadowMaterial = new Material(Shader.Find("Hidden/ShadowVolumes/ShadowRender"));
_blitMaterial = new Material(Shader.Find("Hidden/ShadowVolumes/BlitFlip"));
// set up shader tags
_volumeShader = new ShaderTagId("ShadowVolume");
_occluderShaders = new List<ShaderTagId>
{
new ShaderTagId("UniversalForward"),
new ShaderTagId("UniversalForwardOnly"),
new ShaderTagId("LightweightForward"),
new ShaderTagId("SRPDefaultUnlit")
};
// set up render pass and filter settings
renderPassEvent = RenderPassEvent.BeforeRenderingOpaques;
_filteringSettings = new FilteringSettings(RenderQueueRange.opaque);
}
public override void OnCameraSetup(CommandBuffer cmd, ref RenderingData renderingData)
{
RenderTextureDescriptor cameraTextureDescriptor = renderingData.cameraData.cameraTargetDescriptor;
cameraTextureDescriptor.depthBufferBits = 0;
cmd.GetTemporaryRT(_tempTarget.id, cameraTextureDescriptor, FilterMode.Point);
ConfigureTarget(_tempTarget.Identifier());
}
public override void Configure(CommandBuffer cmd, RenderTextureDescriptor cameraTextureDescriptor)
{
ConfigureClear(ClearFlag.All, Color.white);
}
public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
{
if (!_shadowMaterial) return;
CommandBuffer cmd = CommandBufferPool.Get();
using (new ProfilingScope(cmd, new ProfilingSampler("Shadow Volume Rendering")))
{
// prepare and clear buffer
context.ExecuteCommandBuffer(cmd);
cmd.Clear();
// set matrices
Camera camera = renderingData.cameraData.camera;
cmd.SetViewProjectionMatrices(camera.worldToCameraMatrix, camera.projectionMatrix);
// draw occluders
DrawingSettings occluderSettings = CreateDrawingSettings(_occluderShaders,
ref renderingData, SortingCriteria.CommonOpaque);
occluderSettings.overrideMaterial = _occluderMaterial;
context.DrawRenderers(renderingData.cullResults, ref occluderSettings, ref _filteringSettings);
// draw shadow volume stencil
DrawingSettings volumeSettings = CreateDrawingSettings(_volumeShader,
ref renderingData, SortingCriteria.CommonOpaque);
context.DrawRenderers(renderingData.cullResults, ref volumeSettings, ref _filteringSettings);
// draw shadow material using fullscreen quad
cmd.SetViewProjectionMatrices(Matrix4x4.identity, Matrix4x4.identity);
cmd.DrawMesh(RenderingUtils.fullscreenMesh, Matrix4x4.identity, _shadowMaterial);
cmd.SetViewProjectionMatrices(camera.worldToCameraMatrix, camera.projectionMatrix);
// blit to shadow texture
cmd.Blit(_tempTarget.Identifier(), _shadowMap, _blitMaterial);
}
context.ExecuteCommandBuffer(cmd);
CommandBufferPool.Release(cmd);
}
public override void OnCameraCleanup(CommandBuffer cmd)
{
cmd.ReleaseTemporaryRT(_tempTarget.id);
}
}
}
Here is an example of the differences. Left is scene view, right is game view.
