volumetric: Use non pcf variant for volumetric shadow

data/base/shaders/vk/pointlights.glsl

@@ -74,6 +74,61 @@ vec4 iterateOverAllPointLights(
 	return light;
 }
 
+
+float getShadowVisibilityWithoutPCF(vec3 fragPos)
+{
+	if (WZ_SHADOW_MODE == 0 || WZ_SHADOW_FILTER_SIZE == 0)
+	{
+		// no shadow-mapping
+		return 1.0;
+	}
+	else
+	{
+		// Shadow Mapping
+
+		vec4 fragPosViewSpace = ViewMatrix * vec4(fragPos, 1.0);
+		float depthValue = abs(fragPosViewSpace.z);
+
+		int cascadeIndex = 0;
+
+		// unrolled loop, using vec4 swizzles
+		if (WZ_SHADOW_CASCADES_COUNT > 1)
+		{
+			if (depthValue >= ShadowMapCascadeSplits.x)
+			{
+				cascadeIndex = 1;
+			}
+		}
+		if (WZ_SHADOW_CASCADES_COUNT > 2)
+		{
+			if (depthValue >= ShadowMapCascadeSplits.y)
+			{
+				cascadeIndex = 2;
+			}
+		}
+		if (WZ_SHADOW_CASCADES_COUNT > 3)
+		{
+			if (depthValue >= ShadowMapCascadeSplits.z)
+			{
+				cascadeIndex = 3;
+			}
+		}
+
+		vec4 shadowPos = ShadowMapMVPMatrix[cascadeIndex] * vec4(fragPos, 1.0);
+		vec3 pos = shadowPos.xyz / shadowPos.w;
+
+		if (pos.z > 1.0f)
+		{
+			return 1.0;
+		}
+
+		float bias = 0.0002f;
+
+		return  texture( shadowMap, vec4(pos.xy, cascadeIndex, (pos.z+bias)) );
+	}
+}
+
+
 // based on equations found here : https://www.shadertoy.com/view/lstfR7
 vec4 volumetricLights(
 	vec2 clipSpaceCoord,
@@ -101,7 +156,7 @@ vec4 volumetricLights(
 
 		vec3 od = fogColor.xyz * thickness * length(viewLine / STEPS) / 1000;
 
-		float sunLightEnergy = getShadowVisibility(posOnViewLine) ;
+		float sunLightEnergy = getShadowVisibilityWithoutPCF(posOnViewLine) ;
 		vec3 scatteredLight = vec3(sunLightEnergy) * sunLightColor * od;
 
 		for (int i = 0; i < bucketOffsetAndSize[bucketId].y; i++)