ingar@bibsyst.UUCP (ingar) (06/24/91)
I have tried to program a ray tracing program, but now when i almost have finished I have discovered that my lines isn't lines, they are curves! Can anybody help me?? If you have some source I would be glad. Ingar Pedersen, preIng. ingar@bibsyst.no
krazykid@bass.bu.edu (Ernest Kim) (06/26/91)
In article <382@bibsyst.UUCP> ingar@bibsyst.UUCP (ingar) writes: > > I have tried to program a ray tracing program, but now when >i almost have finished I have discovered that my lines isn't lines, >they are curves! Can anybody help me?? >If you have some source I would be glad. I am not sure of this, but someone told me that gamma correction is used to compensate for the curve of a monitor, so maybe your gamma correction is off for your monitor. Someone please correct me if I am wrong. Ernie krazykid@bu-pub.bu.edu
carter@IASTATE.EDU (Carter Michael Brannon) (06/26/91)
About the curved lines... I had the same problem with my first ray-tracer. May problem was that I had the viewplane too close to the eye-point. Think about it: you're not shooting rays through equispaced points on a SPHERE, but a PLANE. Just move the eye away from the viewplane a bit, and increase the size of the viewplane. Hope this helps! -- Michael B. Carter
rcssjh@minyos.xx.rmit.oz.au (Steven Hayes) (06/26/91)
krazykid@bass.bu.edu (Ernest Kim) writes: >In article <382@bibsyst.UUCP> ingar@bibsyst.UUCP (ingar) writes: >> >> I have tried to program a ray tracing program, but now when >>i almost have finished I have discovered that my lines isn't lines, >>they are curves! Can anybody help me?? >>If you have some source I would be glad. >I am not sure of this, but someone told me that gamma correction is used to >compensate for the curve of a monitor, so maybe your gamma correction is off >for your monitor. Someone please correct me if I am wrong. >Ernie >krazykid@bu-pub.bu.edu I thought gamma correction was to allow for the differences in phosphor intensities on a particular monitor. When I change the gamma value on the SGI PI I sometimes use, the intensities of the colours change! -Steve
jk87377@cc.tut.fi (Juhana Kouhia) (06/27/91)
In article <84569@bu.edu> krazykid@bass.bu.edu (Ernest Kim) writes: >In article <382@bibsyst.UUCP> ingar@bibsyst.UUCP (ingar) writes: >> >> I have tried to program a ray tracing program, but now when >>i almost have finished I have discovered that my lines isn't lines, >>they are curves! Can anybody help me?? >>If you have some source I would be glad. > >I am not sure of this, but someone told me that gamma correction is used to >compensate for the curve of a monitor I don't think curveous of the monitor is behind this; probably he has just fish eye lens caused by error in vector lenght calculation or in projection equation. I remember when I did make my first wireframe program to Commodore VIC-20 -- I made the projection equation myself -- after noting some errors in the picture I noted that I did write fish eye lens; I did fix the program: I divided each line to many short lines in 3D space and projected them separately. Yeah, fish eye projection was more attractive than 'normal' projection. Note that your pictures are now an ART pictures and if you now make a big error to your program and get really false pictures then you're REAL artist and can send your pictures to SIGGRAPH art slide show... :) Juhana Kouhia
carter@IASTATE.EDU (Carter Michael Brannon) (06/27/91)
If straight lines look curved in your ray-traced images, you've probably got your eye point too close to the viewplane. Back the eye away from the viewplane, and back the whole camera away from the scene. -- Michael B. Carter