amir@taux01.nsc.com (Amir J. Katz (Xpert)) (05/14/91)
I am a new user of SunPhigs 1.3. While trying to create a new Phigs program
I encountered the following problem :
When I create elements inside the Phigs structure, using my modeling
coordinates space, if the modeling coordinates size is larger
than ~100, then the element is not displayed on the window.
When I use small coordinates as the modeling coordinates ,
then the display is o.k.
Notice that in all the Phigs examples and tutorials, small coordinate
values are used. (between -2 and ~15)
It seems as if something is wrong with the translation from
the modeling coordinates (MC) to the world coordinates (WC).
Example :
The coordinates in file pickit.c
( in phigs1.3/examples directory) are :
static Ppoint3 square[] = { 0.0,0.0,0.0,
0.2,0.0,0.0,
0.2,0.2,0.0,
0.0,0.2,0.0,
0.0,0.0,0.0
};
I changed them to be :
static Ppoint3 square[] = { 0.0,0.0,0.0,
200.0,0.0,0.0,
200.0,200.0,0.0,
0.0,200.0,0.0,
0.0,0.0,0.0
};
and with those new coordinates , the pickit program does not work -
nothing is displayed on the window !!
-- TIA,
--
Amir J. Katz, System Manager
Internet: amir%pilat.UUCP@taux01.nsc.com
UUCP: {decwrl,uunet,...}!nsc!taux01!amir
Phone: +972 52-570713
Fax: +972 52-570719
Snail-mail: Amir J. Katz, Silvaco Israel Ltd.
19 Maskit St., Herzelia, Israel 46733levine@well.sf.ca.us (Ron Levine) (05/18/91)
In article <AMIR.91May14133330@taux01.nsc.com>, amir@taux01.nsc.com (Amir J. Katz (Xpert)) writes: > > I am a new user of SunPhigs 1.3. While trying to create a new Phigs program > I encountered the following problem : > > When I create elements inside the Phigs structure, using my modeling > coordinates space, if the modeling coordinates size is larger > than ~100, then the element is not displayed on the window. > > When I use small coordinates as the modeling coordinates , > then the display is o.k. ....... > -- > Amir J. Katz, System Manager Amir: I don't have the SunPHIGS examples manual you refer to, so I'm not sure exacly what primitive you are using, what attributes you are setting, what modeling transformations you are specifying, or what you are doing about the view definition, but I suspect that you are simply putting all of the visible points of your square outside of the view volume. Understand that in the default view, only points lying in the unit cube in world space, 0 <= x,y,z <= 1 are visible. In any view, only points which map to the unit cube in NPC space can be visible. If your primitive is a polyline or a fill area with interior style empty or hollow, then only the edges of the square are visible. You are probably making the square so large that the edges all fall outside the defined view volume, whatever it is. Ron Levine (415)-535-1350