Doubling the resolution, yes ... doubling the pixel density, no
I hope the mobile phone/tablet industry will provide us with even more cheap pixels in the years to come. Shouldn't be a problem to render simple worlds in 2560x1600 ... i mean an Android tablet can do it and iPads could probably do it if they had such a display.
Okay your comment about going from 1280x720 to 1920x1080 only doubling resolution and not pixel density doesn't make sense to me. If you have a 7" screen with a 720p resolution (1024000 pixels) and then on the same size 7" screen go to 1080p (2073600 pixels) how are you "not" doubling the pixel density? Same size screen+double the pixels=double the pixel density
. Is that not correct? If I am incorrect, where is the flaw in my logic. Please explain.
Well, yeah, if you measure "pixel density
" in Pixels Per SQUARE INCH
, then you are correct. But the numbers you are disputing are PPI (Pixels Per INCH
), which is like comparing Apples
(different units of measurement).
So instead, let's compare PPI, which is how "pixel density" is typically measured.
Doubling the PPI would double both X and Y dimensions, which would quadruple (4x) the pixels per square inch. A 1080p display has TWICE as many pixels (2x) as a 720p display, not 4x.
The diagonal 7-inch dimension is only approximate, so I do some rounding here: 1280x720 display PPI calculation:
Horizontal x = 1280 pixels.
Vertical y = 720 pixels.
Diagonal d = sqrt(x*x + y*y) = sqrt(1280*1280 + 720*720) = sqrt(1638400 + 518400) = sqrt(2156800) = 1469 pixels.
PPI = 1469 pixels / 7 inches = 210 PP
I.1920x1080 display PPI calculation:
Horizontal x = 1920 pixels.
Vertical y = 1080 pixels.
Diagonal d = sqrt(x*x + y*y) = sqrt(1920*1920 + 1080*1080) = sqrt(368400 + 1166400) = sqrt(4852800) = 2203 pixels.
PPI = 2203 pixels / 7 inches = 315 PPI
.720p to 1080p PPI increase:
(315 - 210)/210 * 100% = 50% increase in PPI
What is curious is why doubling the pixels per square inch did not increase the PPI by a ratio of sqrt(2) as I had expected (i.e. 41% increase). Hmm... EDIT: Ahh... I see. 1080p has slightly more than twice the pixels of a 1280x800 display like the Rift DK uses, but the calculations above were for the 720p display (less pixels) that was being discussed. That accounts for the difference between 50% and 41% increase in PPI...
And now, for something COMPLETELY DIFFERENT!