devans@SNOWHITE.CIS.UOGUELPH.CA (05/24/91)
A while ago I posted a question about shading differences between a VGX and a PI (basically the PI looked much more blended, while the VGX was "mathematically" correct, but rather harsh.) It just hit me that the cause was the fact that PIs have only 24 bitplanes. So, when I used double buffering, I really got 12 planes per buffer. Then the pipeline dithered to make the colours look OK. I have no idea how many planes the VGX has (I'd be interrested in knowning, though...), but I'm sure it would have 48....so it could do full 24-bit double-buffering. That would explain the "soft" vs. "hard" look This seems too simple...am I right in my assumption?
andreess@mrlaxs.mrl.uiuc.edu (Marc Andreessen) (05/31/91)
In article <9105232209.AA01931@snowhite.cis.uoguelph.ca> devans@SNOWHITE.CIS.UOGUELPH.CA writes: > It just hit me that the cause was the fact that PIs have only 24 >bitplanes. So, when I used double buffering, I really got 12 planes >per buffer. Then the pipeline dithered to make the colours look OK. >I have no idea how many planes the VGX has (I'd be interrested in >knowning, though...), but I'm sure it would have 48....so it could >do full 24-bit double-buffering. That would explain the "soft" vs. >"hard" look > This seems too simple...am I right in my assumption? Yup... this is true on IBM RS/6000 24-bit boards also (12 bits/buffer with dithering). Marc -- Marc Andreessen___________University of Illinois Materials Research Laboratory Internet: andreessen@uimrl7.mrl.uiuc.edu____________Bitnet: andreessen@uiucmrl