(HW) DXTx VS BC7 Compression - VRAM/RAM usage vs HDD usage
Posted: Wed Dec 16, 2020 11:05 pm
Hi, Im really wondering...
In Unity I can set up either Normal (DXTx) or High (BC7) quality of texture compression.
BC7 is on average 2x the size of the file on HDD. Question is, if it is also 2x the size when actually loaded in the VRAM/RAM?
To me it appears its not, but its not so easy to test it properly, doing the same type of long gameplay twice etc.
I just tested it with terrain texture in both variants and the VRAM/RAM usage was exactly the same.
So this leads me to the conclusion, that once its loaded in the VRAM or RAM, these formats take up the same space.
Am I right about it? Or am I missing something?
Also, any general opinions on DXTx vs BC7 in DREAM/DFU? Like
"use BC7 in these cases and DXT in these cases" etc?
"BC7 for normals, DXT for rest?"
"BC7 for sprites with alpha...?"
"Never use XX...?"
Thanks a lot!
PS: Found this very detailed compression article, really good stuff, but no answers to my questions it seems
http://sv-journal.org/2014-1/06/en/index.php?lang=en
In Unity I can set up either Normal (DXTx) or High (BC7) quality of texture compression.
BC7 is on average 2x the size of the file on HDD. Question is, if it is also 2x the size when actually loaded in the VRAM/RAM?
To me it appears its not, but its not so easy to test it properly, doing the same type of long gameplay twice etc.
I just tested it with terrain texture in both variants and the VRAM/RAM usage was exactly the same.
So this leads me to the conclusion, that once its loaded in the VRAM or RAM, these formats take up the same space.
Am I right about it? Or am I missing something?
Also, any general opinions on DXTx vs BC7 in DREAM/DFU? Like
"use BC7 in these cases and DXT in these cases" etc?
"BC7 for normals, DXT for rest?"
"BC7 for sprites with alpha...?"
"Never use XX...?"
Thanks a lot!
PS: Found this very detailed compression article, really good stuff, but no answers to my questions it seems
http://sv-journal.org/2014-1/06/en/index.php?lang=en