rleyden@pnet02.cts.com (Rich Leyden) (12/11/87)
I've been puzzling over a few features of DBW_Render 2.0, ray tracing program. Unlike Render 1.0, this version allows any size image up to 1024 x1024. However, as far as I can tell, the display routine always uses a 312x400 screen. So, for example, a 350x400 image will nicely be displayed using the overscan region of the monitor screen but a 624x400 image will only have the center most portion of the image visible. If this file is loaded into some other program capable of displaying a 640x400 HAM image, Digi-View is handy, only the right half of the scene is shown. This seemed a little strange to me so I looked at the IFF file header. It shows the width 612 and the height 400 (02700190 hexadecimal) for both the image and the page. Is there something else which defines how an image is displayed? I liked DBW_Render, both versions a lot. But the manual for 2.0 seems a little crytic. Its really not a manual at all but a glossy of terms with line numbers to serve as the "key" for their key word copy protection scheme. For example, there is no discussion that I could find of the "mode" setting.
peter@sugar.UUCP (Peter da Silva) (12/15/87)
[IFF file at 640 by 400 didn't show up in hires/lace] Look at the contents of the CAMG chunk in the IFF file. It may not have set the HIRES bit in the viewport mode. -- -- Peter da Silva `-_-' ...!hoptoad!academ!uhnix1!sugar!peter -- Disclaimer: These U aren't mere opinions... these are *values*.
wecker@child.dec.com (A wholly oned subsidiary of DEC) (12/22/87)
Hi folks... remember me? Sorry I've been so quiet but others seem to be keeping the conference busy and I've been away quite a bit (just got back from SCUBA diving in the Galapagos Islands). Anyway... > I've been puzzling over a few features of DBW_Render 2.0, ray tracing >program. Unlike Render 1.0, this version allows any size image up to 1024 >x1024. However, as far as I can tell, the display routine always uses a Actually the 1024x1024 range was put in for people with frame buffers. You can do any picture within the overscan limits (like 352x464) with no problem. Anything over that you are on your own... (caveat emptor) >312x400 screen. So, for example, a 350x400 image will nicely be displayed >using the overscan region of the monitor screen but a 624x400 image will >only have the center most portion of the image visible. If this file is >loaded into some other program capable of displaying a 640x400 HAM image, WRONG... hardware on the AMIGA only supports HAM in LOW-RES mode if you try to go to HAM in HI-RES (640+ columns) you will crash the machine. This is layed out very plainly in the RKM. >Digi-View is handy, only the right half of the scene is shown. This seemed >a little strange to me so I looked at the IFF file header. It shows the >width 612 and the height 400 (02700190 hexadecimal) for both the image and >the page. Is there something else which defines how an image is displayed? No that's it. The program is setting limits to keep you from crashing the world > I liked DBW_Render, both versions a lot. But the manual for 2.0 seems a >little crytic. Its really not a manual at all but a glossy of terms with >line numbers to serve as the "key" for their key word copy protection >scheme. For example, there is no discussion that I could find of the "mode" >setting. This might help a little bit: 1) Mode 0 = full ray tracing 1 = follow a ray until it hits an object then STOP (sketch mode) 2 = same as mode 1, but stops when it hits an EXTENT (good with superquads and fractal objects) Use mode 1 when you are designing a picture, much MUCH faster! 2) bpp = 4 for all amiga pictures 4 bits/pixel/gun = 4096 colors = 8 for frame buffer pictures 8 bits/pixel/gun = 16777216 3) When you are designing a picture try computing it in "postage stamp" size e.g.: scan from 0 to 40 rows 40 columns 40 mode 1 bpp 4 This should give you a speed up of at least 800 over a standard command line like: scan from 0 to 320 rows 320 columns 400 mode 0 bpp 4 4) Note that when you rescale the picture (like from 320x400 to 40x40 as above) you will see the SAME PICTURE. The program is smart enough to rescale the entire picture. You will ALWAYS have a virtual +-128 rows and columns at the focal point. For example if you look from point 0,0,100 at point 0,0,0 all points at Z=0 between X=<-128,+128> and Y=<-128,+128> are visable. I hope this helps some. Best Regards, ___________________________________________________________________________ dave ENET: CHILD::WECKER - DTN: 522_3873 - MS: CXO1-2/N22 USENET: decwrl!child.dec.com!wecker ARPA: wecker%child.dec.com@decwrl.dec.com SNAIL: 115 Palm Springs Drive, Colorado Springs CO 80921 Disclaimer: The opinions expressed are my own and in no way should be taken as representative of my employer Digital Equipment Corporation. ___________________________________________________________________________
sean@ms.uky.edu (Sean Casey) (12/22/87)
In article <8712212035.AA11337@decwrl.dec.com> wecker@child.dec.com (A wholly oned subsidiary of DEC) writes: >> I liked DBW_Render, both versions a lot. But the manual for 2.0 seems a >>little crytic. Its really not a manual at all but a glossy of terms with >>line numbers to serve as the "key" for their key word copy protection >>scheme. Oh tell me oh please tell me that you didn't allow someone to use "Look Up A Word In The Manual" copy protection in one of your fine programs... Sean -- -- Sean Casey sean@ms.uky.edu, sean@UKMA.BITNET -- (the Empire guy) {rutgers,uunet,cbosgd}!ukma!sean -- University of Kentucky in Lexington Kentucky, USA -- "Inconceivable!"