- Disabled SkyRendering when no HDRI is present.

- Temporarily disabled DynamicGI.UpdateEnvironment() call for now (was too slow if done each frame).

Assets/ScriptableRenderLoop/HDRenderLoop/Sky/SkyRenderer.cs

 
         }
 
+        bool IsSkyValid(SkyParameters parameters)
+        {
+            // Later we will also test shader for procedural skies.
+            return parameters.skyHDRI != null;
+        }
+
         private void RenderSky(Camera camera, SkyParameters skyParameters, bool forceUVBottom, RenderLoop renderLoop)
         {
             Mesh skyMesh = BuildSkyMesh(camera, forceUVBottom);
 
         public void RenderSky(Camera camera, SkyParameters skyParameters, RenderTargetIdentifier colorBuffer, RenderTargetIdentifier depthBuffer, RenderLoop renderLoop)
         {
-            // Render sky into a cubemap - doesn't happen every frame, can be control
-            for (int i = 0; i < 6; ++i)
+            if (IsSkyValid(skyParameters))
-                Utilities.SetRenderTarget(renderLoop, m_SkyboxCubemapRT, "", 0, (CubemapFace)i);
-                Camera faceCamera = m_CubemapFaceCamera[i].GetComponent<Camera>();
-                RenderSky(faceCamera, skyParameters, true, renderLoop);
-            }
+                // Render sky into a cubemap - doesn't happen every frame, can be control
+                for (int i = 0; i < 6; ++i)
+                {
+                    Utilities.SetRenderTarget(renderLoop, m_SkyboxCubemapRT, "", 0, (CubemapFace)i);
+                    Camera faceCamera = m_CubemapFaceCamera[i].GetComponent<Camera>();
+                    RenderSky(faceCamera, skyParameters, true, renderLoop);
+                }
-            m_StandardSkyboxMaterial.SetTexture("_Tex", m_SkyboxCubemapRT);
-            RenderSettings.skybox = m_StandardSkyboxMaterial; // 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.ambientMode = UnityEngine.Rendering.AmbientMode.Skybox; // Force skybox for our HDRI
-            RenderSettings.reflectionIntensity = 1.0f;
-            DynamicGI.UpdateEnvironment();
+                m_StandardSkyboxMaterial.SetTexture("_Tex", m_SkyboxCubemapRT);
+                RenderSettings.skybox = m_StandardSkyboxMaterial; // 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.ambientMode = UnityEngine.Rendering.AmbientMode.Skybox; // Force skybox for our HDRI
+                RenderSettings.reflectionIntensity = 1.0f;
+                //DynamicGI.UpdateEnvironment();
-            // TODO: do a render to texture here
+                // TODO: do a render to texture here
-            // Downsample the cubemap and provide it to Enlighten
+                // Downsample the cubemap and provide it to Enlighten
-            // TODO: currently workaround is to set the cubemap in a Skybox/cubemap material
-            //m_SkyboxMaterial.SetTexture(cubemap);
+                // TODO: currently workaround is to set the cubemap in a Skybox/cubemap material
+                //m_SkyboxMaterial.SetTexture(cubemap);
-            // Render the sky itself
-            Utilities.SetRenderTarget(renderLoop, colorBuffer, depthBuffer, "Sky Pass");
-            RenderSky(camera, skyParameters, false, renderLoop);
+                // Render the sky itself
+                Utilities.SetRenderTarget(renderLoop, colorBuffer, depthBuffer, "Sky Pass");
+                RenderSky(camera, skyParameters, false, renderLoop);
+
+            }
         }
     }
 }