Stretched preview before rendering new frame

[dedoardo]

Resizing the houdini viewport typically causes the previous frame to be rendered stretched (nearest neighbor) before the new frame begins to be blit.

The stretched image can be replaced by a solid background or similar in here

[dedoardo]

On a similar note, if you switch scene you can see the last frame from the previous scene while the new one renders.
RenderBuffers should probably be cleared when the render session terminates.