Mario, I documented this:
http://www.starfireresearch.com/services/java3d/supplementalDocumentation.html#ClippingValues >From the information provided by Kevin Rushforth - Sun Engineer - March 9, 2001. As you can see the value will change based on screen size and such. - John Wright Starfire Research "ZACZEK, MARIUSZ P. (MARIO) (JSC-DM) (NASA)" wrote: > > actually, I might have to disagree now...I did a quick test using > SimpleUniverse which > is supposed to put your eye at 2.41 m from the center. I then put an object > at 0,0,0 with > a set of axes there as well. When I first start the view I am looking down > the Z axis (0,0,2.41) > towards the center (0,0,0) and see everything when I have a small > frontclipdistance. > > But, when I set my front clip distance to 0.54 I see my object cut off, and > still see my axes. > When I go to 0.55 I no longer see my object and no longer see the axes...( I > did other tests > as well). My conclusion is then that the actual factor (you mention 7) is > closer to 4.38 (2.41/0.55) > which baffels me even more now. Note that for my other code I am using > VirtualUniverse so this > 2.41 distance is removed from my view but I still see a wierd clipping > issue. > > Thanks > > Mario > > -----Original Message----- > From: ZACZEK, MARIUSZ P. (MARIO) (JSC-DM) (NASA) > Sent: Friday, June 06, 2003 6:48 PM > To: [EMAIL PROTECTED] > Subject: Re: [JAVA3D] ? Clipdistance ratio = 3000 ... please explain ? > > how did you find out you have to multiply by 7? And how do you know this is > correct? > > I just did a quick demo using SimpleUniverse (other code I use > VirtualUniverse) and > you are correct...this is really wierd. Is it documented anywhere on the > javadocs and > I just missed it? (or, I did not look hard enough :) ) > > thanks, > > .... now if someone can only help me with the ratio question ;) > > Mario > > Mariusz Zaczek > NASA - Johnson Space Center > Automated Vehicles and Orbit Analysis / DM35 > Flight Design and Dynamics Division > Mission Operations Directorate > Bldg: 30A Room: 3040A > > Disclaimer: "The opinions, observations and comments expressed in my email > are strictly my own and do not necessarily reflect those of > NASA." > > -----Original Message----- > From: John Wright [mailto:[EMAIL PROTECTED] > Sent: Friday, June 06, 2003 6:40 PM > To: [EMAIL PROTECTED] > Subject: Re: [JAVA3D] ? Clipdistance ratio = 3000 ... please explain ? > > Multiply your clip values by 7 to get the actual distances the clipping > occurs at. I've got this documented on my website page of notes (as > I've posted to the list before). > > - John Wright > Starfire Research > > "ZACZEK, MARIUSZ P. (MARIO) (JSC-DM) (NASA)" wrote: > > > > Also, > > What exactly is the front clip plane distance? This may sound like a > > stupid question, but I am seeing clipping of objects before I even reach > > this distance. I tested with a front clip distance of 0.05 but before I > > even go 0.2 away from the object, the object got clipped. And YES, the > > object > > is at 0,0,0 (well, actually, it's at another point but I use > OrbitBehavior > > to set my rotation center on this object...and NO, this is not the cause > > of the > > clip because the actual object is far away from the ORIGINAL center > point > > so that > > rbitBehavior's setRotationCenter() function would probably show clipping > > at even > > greater distance if this was the problem.) > > > > SO, I am trying to understand this clipping better and if you have > > comments please > > let me know. > > > > Thanks, > > Mario > > > > -----Original Message----- > > From: ZACZEK, MARIUSZ P. (MARIO) (JSC-DM) (NASA) > > Sent: Friday, June 06, 2003 4:25 PM > > To: [EMAIL PROTECTED] > > Subject: [JAVA3D] ? Clipdistance ratio = 3000 ... please explain ? > > > > Hi, > > My question has to do with the Back-to-Front clip plane distance ratio > > which is > > recommened as being 3000 (although it can be more but with degredation). > > > > Take the case of a Solar System simulation where we have an Earth centered > > system > > containing an orbiting vehicle and the Moon. > > > > Earth Radius = ~ 6,400,000 m > > Vehicle altitude above earth = ~ 400,000 m > > Moon, Distance to Earth = ~ 380,000,000 m > > > > Say I have a vehicle which is orbiting around the earth and I am using a > > camera to > > follow this vehicle. Say the altitude is 400,000 m (400km...low earth > > orbit) > > ...IF I want to be able to have a 1 m resolution (1 m front clip distance) > > and still > > be able to see the earth below then I have to have a back clip distance of > > at least > > 400,000 ... which means the ratio is 400,000!!!!! This is 100+ times what > > the recommended > > ratio of 3000. > > > > Even worse, if I am following this vehicle as it orbits the moon and want > to > > keep the > > 1 m distance from the vehicle and still see the earth (maybe see an Earth > > Rise) then the ratio > > is 380,000,000 to 1 .... WAY ABOVE the 3000 recommended. > > > > SO, my problem is that I want to be able to have the ability to zoom close > > to a vehicle > > and still be able to see earth below it....and more importantly be able to > > see other vehicles > > that are going to rendezvous with mine but are far away...more than 3000 m > > away. > > > > For the most part, going higher than 3000 is ok for some things, but in > > other cases that > > I've come across, if I go above a ratio of 50,000 I get merging of > > geometries...ie, I see > > things behind the earth that should not be visible. > > > > Please give me suggestions to overcome this problem? ... should I be using > a > > different > > "policy" for the back/front clip planes? Oh, and, explain it to me as if I > > was a 3 year old > > so I can easily implement it. > > > > Thank you for your help, > > > > Mario > > > > Mariusz Zaczek > > NASA - Johnson Space Center > > Automated Vehicles and Orbit Analysis / DM35 > > Flight Design and Dynamics Division > > Mission Operations Directorate > > Bldg: 30A Room: 3040A > > > > Disclaimer: "The opinions, observations and comments expressed in my email > > are strictly my own and do not necessarily reflect those of > > NASA." > > > > > =========================================================================== > > To unsubscribe, send email to [EMAIL PROTECTED] and include in the > body > > of the message "signoff JAVA3D-INTEREST". For general help, send email to > > [EMAIL PROTECTED] and include in the body of the message "help". > > > > > =========================================================================== > > To unsubscribe, send email to [EMAIL PROTECTED] and include in the > body > > of the message "signoff JAVA3D-INTEREST". For general help, send email to > > [EMAIL PROTECTED] and include in the body of the message "help". > > =========================================================================== > To unsubscribe, send email to [EMAIL PROTECTED] and include in the body > of the message "signoff JAVA3D-INTEREST". For general help, send email to > [EMAIL PROTECTED] and include in the body of the message "help". > > =========================================================================== > To unsubscribe, send email to [EMAIL PROTECTED] and include in the body > of the message "signoff JAVA3D-INTEREST". For general help, send email to > [EMAIL PROTECTED] and include in the body of the message "help". > > =========================================================================== > To unsubscribe, send email to [EMAIL PROTECTED] and include in the body > of the message "signoff JAVA3D-INTEREST". For general help, send email to > [EMAIL PROTECTED] and include in the body of the message "help". =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff JAVA3D-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
