Merge pull request #601 from Unity-Technologies/Branch_ShadowAndSkyBugfix

Branch shadow and sky bugfix

ScriptableRenderPipeline/Core/Shadow/Shadow.cs

         {
             m_Shadowmap = new RenderTexture( (int) m_Width, (int) m_Height, (int) m_ShadowmapBits, m_ShadowmapFormat, RenderTextureReadWrite.Linear );
             CreateShadowmap( m_Shadowmap );
+            m_Shadowmap.Create();
         }
 
         virtual protected void CreateShadowmap( RenderTexture shadowmap )

ScriptableRenderPipeline/HDRenderPipeline/Sky/SkyManager.cs

                 using (new ProfilingSample(cmd, "DynamicGI.UpdateEnvironment"))
                 {
                     // TODO: Properly send the cubemap to Enlighten. Currently workaround is to set the cubemap in a Skybox/cubemap material
+                    float intensity = IsSkyValid() ? 1.0f : 0.0f; // Eliminate all diffuse if we don't have a skybox (meaning for now the background is black in HDRP)
-                    RenderSettings.skybox = IsSkyValid() ? m_StandardSkyboxMaterial : null; // Setup this material as the default to be use in RenderSettings
-                    RenderSettings.ambientIntensity = 1.0f; // fix this to 1, this parameter should not exist!
+                    RenderSettings.skybox = m_StandardSkyboxMaterial; // Setup this material as the default to be use in RenderSettings
+                    RenderSettings.ambientIntensity = intensity;
-                    RenderSettings.reflectionIntensity = 1.0f;
+                    RenderSettings.reflectionIntensity = intensity;
                     RenderSettings.customReflection = null;
                     DynamicGI.UpdateEnvironment();