public Vector4 ReserveDirectionalShadows(Light light, int visibleLightIndex)
{
if (currentDirectionalLightShadowCount < maxDirectionalShadowCount && light.shadows != LightShadows.None && light.shadowStrength > 0f)
{
float maskChannel;
LightBakingOutput lightBakingOutput = light.bakingOutput;
if (lightBakingOutput.lightmapBakeType == LightmapBakeType.Mixed && lightBakingOutput.mixedLightingMode == MixedLightingMode.Shadowmask)
{
useShadowMask = true;
maskChannel = lightBakingOutput.occlusionMaskChannel; // can not use the light index because it may be changed in runtime
}
else
{
maskChannel = -1;
}
// GetShadowCasterBounds now returns true for directional lights even when there is nothing within the shadow range
if (!cullingResults.GetShadowCasterBounds(visibleLightIndex, out Bounds b))
{
// the shadow strength of light is negative, see GetDirectionalShadowAttenuation in WindsmoonShadow.hlsl
// if the stength is positive, the shader may be handle the shadow as realtime shadow
return(new Vector4(-light.shadowStrength, 0f, 0, maskChannel));
}
directionalShadows[currentDirectionalLightShadowCount] = new DirectionalShadow()
{
visibleLightIndex = visibleLightIndex, slopeScaleBias = light.shadowBias, nearPlaneOffset = light.shadowNearPlane
};
return(new Vector4(light.shadowStrength, shadowSettings.DirectionalShadowSetting.CascadeCount * currentDirectionalLightShadowCount++, light.shadowNormalBias, maskChannel));
}
return(new Vector4(0f, 0f, 0f, -1));
}
private void RenderDirectionalShadow(int index, int splitCount, int tileSize)
{
DirectionalShadow directionalShadow = directionalShadows[index];
ShadowDrawingSettings shadowDrawingSettings = new ShadowDrawingSettings(cullingResults, directionalShadow.visibleLightIndex);
int cascadeCount = shadowSettings.DirectionalShadowSetting.CascadeCount;
int tileOffset = index * cascadeCount;
Vector3 cascadeRatios = shadowSettings.DirectionalShadowSetting.CascadeRatios;
float cascadeCullingFactor = Mathf.Max(0f, 0.8f - shadowSettings.DirectionalShadowSetting.CascadeFade); // control how much shadow casters will cast shadow in larger cascade
float inversedSplitCount = 1f / splitCount;
for (int i = 0; i < cascadeCount; ++i)
{
// note : the split data contains information about how shadow caster objects should be culled
cullingResults.ComputeDirectionalShadowMatricesAndCullingPrimitives(directionalShadow.visibleLightIndex, i, cascadeCount,
cascadeRatios, tileSize, directionalShadow.nearPlaneOffset, out Matrix4x4 viewMatrix, out Matrix4x4 projectionMatrix, out ShadowSplitData shadowSplitData);
shadowSplitData.shadowCascadeBlendCullingFactor = cascadeCullingFactor;
shadowDrawingSettings.splitData = shadowSplitData;
if (index == 0) // set culling spheres, all directional light use only one group of culling spheres
{
// note : as the shadow projections are orthographic and square they end up closely fitting their culling sphere, but also cover some space around them
// that's why some shadows can be seen outside the culling regions
// also the light direction doesn't matter to the sphere, so all directional lights end up using the same culling spheres
// the camera is not at the sphere's center, but the surface of the sphere, all spheres will intersect at this point
Vector4 cullingSphere = shadowSplitData.cullingSphere; // w means sphere's radius
SetCascadeInfo(i, cullingSphere, tileSize);
}
int tileIndex = tileOffset + i;
SetShadowMapViewport(tileIndex, splitCount, tileSize, out Vector2 offset);
// Matrix4x4 vpMatrix = projectionMatrix * viewMatrix
directionalShadowMatrices[tileIndex] = ConvertClipSpaceToTileSpace(projectionMatrix * viewMatrix, offset, inversedSplitCount);
// directionalShadowMatrices[index] = projectionMatrix * viewMatrix;
commandBuffer.SetViewProjectionMatrices(viewMatrix, projectionMatrix);
commandBuffer.SetGlobalDepthBias(0f, directionalShadow.slopeScaleBias);
ExecuteBuffer();
renderContext.DrawShadows(ref shadowDrawingSettings);
commandBuffer.SetGlobalDepthBias(0f, 0f);
}
}
public Vector3 ReserveDirectionalShadows(Light light, int visibleLightIndex)
{
// GetShadowCasterBounds return true if the light affects at least one shadow casting object in the Scene
if (currentDirectionalLightShadowCount >= maxDirectionalShadowCount || light.shadows == LightShadows.None || light.shadowStrength <= 0f ||
cullingResults.GetShadowCasterBounds(visibleLightIndex, out Bounds bouds) == false)
{
return(Vector3.zero);
}
LightBakingOutput lightBakingOutput = light.bakingOutput;
if (lightBakingOutput.lightmapBakeType == LightmapBakeType.Mixed && lightBakingOutput.mixedLightingMode == MixedLightingMode.Shadowmask)
{
useShadowMask = true;
}
directionalShadows[currentDirectionalLightShadowCount] = new DirectionalShadow()
{
visibleLightIndex = visibleLightIndex, slopeScaleBias = light.shadowBias, nearPlaneOffset = light.shadowNearPlane
};
return(new Vector3(light.shadowStrength, shadowSettings.DirectionalShadowSetting.CascadeCount * currentDirectionalLightShadowCount++, light.shadowNormalBias));
}
