render bigger. All web graphics are meant to be displayed at 72 pixels per inch. Print graphics are usually 300 dots per inch on paper, which is the same as 300 pixels per inch on screen. This means to get a higher resolution, the image must be a LOT larger on your screen (divide 300 by 72) For sharper VR images, use larger renders. Remember that for any typical VR, the resolution is decreased by a factor of four, because you only see about a fourth of the image at a time. For example, if you start with an 800x600, in the VR you are only seeing a 200 pixel width at once, but the size of the window will be much larger. Therefore, try rendering at 4 times the size for your VR images.