Problem creating imposters using Render to Texture BP Toolset

I’m trying to follow the technique outlined in the documentation here: Render 3D Imposter Sprites | Unreal Engine Documentation

I’ve followed the instructions exactly, but for some reason the output I’m getting has an error in the images. The BaseColor, Opacity and WorldNormal all look like this:

One thing I noticed is that although I select ‘Include Buffer Visualisation Targets’ on the High Resolution Screenshot window, it gets immediately disabled as soon as I type “ke * rendertextures” into the command console. This seems strange, and might point to the underlying issue here, but I don’t know.

Additionally, I don’t seem able to set the multiplier higher than 4x, which gives an output image of 2048x2048. The documentation states that its possible to create outputs up to 8192x8192, so I’m not sure why I am not able to go higher than 2K.

I am using UE version 4.19.

Anyone know what might be happening here?

OK, so the first problem was because I was using forward rendering. Switching back to deferred fixed that.

But I’m still having two issues:

  1. The resolution won’t go higher than 2048*2048

  2. I cannot seem to export an opacity/mask for the object. I can work around this by running a separate pass with pure white as base colour, but its a bit annoying.