Fixed issue that was causing offscreen camera to render black when either depth or opaque color was requested.

com.unity.render-pipelines.lightweight/LWRP/LightweightForwardRenderer.cs

                 EnqueuePass(cmd, RenderPassHandles.LocalShadows, baseDescriptor);
 
             bool requiresDepthAttachment = requiresCameraDepth && !requiresDepthPrepass;
-            bool requiresColorAttachment = RequiresColorAttachment(ref renderingData.cameraData, baseDescriptor) || requiresDepthAttachment;
+            bool requiresColorAttachment = RequiresIntermediateColorTexture(ref renderingData.cameraData, baseDescriptor, requiresDepthAttachment);
             int[] colorHandles = (requiresColorAttachment) ? new[] {RenderTargetHandles.Color} : null;
             int depthHandle = (requiresColorAttachment) ? RenderTargetHandles.DepthAttachment : -1;
             EnqueuePass(cmd, RenderPassHandles.ForwardLit, baseDescriptor, colorHandles, depthHandle, renderingData.cameraData.msaaSamples);
 
         public RenderTargetIdentifier GetSurface(int handle)
         {
+            if (handle == -1)
+                return BuiltinRenderTextureType.CameraTarget;
+
-            if (handle < 0 || !m_ResourceMap.TryGetValue(handle, out renderTargetID))
+            if (!m_ResourceMap.TryGetValue(handle, out renderTargetID))
             {
                 Debug.LogError(string.Format("Handle {0} has not any surface registered to it.", handle));
                 return new RenderTargetIdentifier();
                 m_ActiveRenderPassQueue.Add(pass);
         }
 
-        bool RequiresColorAttachment(ref CameraData cameraData, RenderTextureDescriptor baseDescriptor)
+        bool RequiresIntermediateColorTexture(ref CameraData cameraData, RenderTextureDescriptor baseDescriptor, bool requiresCameraDepth)
+            if (cameraData.isOffscreenRender)
+                return false;
+
-            return cameraData.isSceneViewCamera || isScaledRender || cameraData.isHdrEnabled ||
+            return requiresCameraDepth || cameraData.isSceneViewCamera || isScaledRender || cameraData.isHdrEnabled ||
                 cameraData.postProcessEnabled || cameraData.requiresOpaqueTexture || isTargetTexture2DArray;
         }