Merge pull request #1371 from EvgeniiG/master

Fix banding issues caused by high intensity volumetric lighting

ScriptableRenderPipeline/HDRenderPipeline/CHANGELOG.md

 - Fix line lights sent to the lightmappers. The backends don't support this light type.
 - Fix issue with shadow mask framesettings not correctly taken into account when shadow mask is enabled for lighting.
 - Fix directional light and shadow mask transition, they are now matching making smooth transition
+- Fix banding issues caused by high intensity volumetric lighting
 
 ## [2018.1.0f2]
 

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/Volumetrics/VBuffer.hlsl

                                 bool   quadraticFilterXY)
 {
     // TODO: add some slowly animated noise to the reconstructed value.
-    return FastTonemapInvert(SampleVBuffer(TEXTURE3D_PARAM(VBufferLighting, clampSampler),
+    // TODO: re-enable tone mapping after implementing pre-exposure.
+    return /*FastTonemapInvert*/(SampleVBuffer(TEXTURE3D_PARAM(VBufferLighting, clampSampler),
                                            positionNDC,
                                            linearDepth,
                                            VBufferResolution,

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/Volumetrics/VolumetricLighting.compute

         // Note: for correct filtering, the data has to be stored in the perceptual space.
         // This means storing the tone mapped radiance and transmittance instead of optical depth.
         // See "A Fresh Look at Generalized Sampling", p. 51.
-        _VBufferLightingIntegral[voxelCoord] = float4(FastTonemap(totalRadiance), Transmittance(opticalDepth));
+        // TODO: re-enable tone mapping after implementing pre-exposure.
+        _VBufferLightingIntegral[voxelCoord] = float4(/*FastTonemap*/(totalRadiance), Transmittance(opticalDepth));
 
         // Compute the optical depth up to the end of the interval.
         opticalDepth += 0.5 * extinction * dt;