Separate downsampled translucency manually updates the view uniform buffer without invalidating the cached view.

In TranslucencyRendering.cpp, FDeferredShadingSceneRenderer::RenderTranslucency, the following code:

FViewUniformShaderParameters DownsampledTranslucencyViewParameters;
SetupDownsampledTranslucencyViewParameters(RHICmdList, View, DownsampledTranslucencyViewParameters);
Scene->UniformBuffers.ViewUniformBuffer.UpdateUniformBufferImmediate(DownsampledTranslucencyViewParameters);

Manually updates the view uniform buffer parameters without clearing out the cached view. This later causes the view uniform buffer to not get updated back to the full screen parameters.

This issue cropped up with a UDN customer who was adding a second translucency pass.

https://udn.unrealengine.com/questions/500847/issue-with-updateviewuniformbuffer-during-rendertr.html