Re: [Algorithms] Huge world, little precision From: Gino van den Bergen - 2007-03-01 15:16:35 ```The discussion on rotations was triggered by my remark that you'd better not do rotations for fixed-point coordinates. What Johns is saying, and what I should have explained more carefully is that it is not necessary to perform the rotation to view space in order to solve the accuracy problem. Only do the translation and leave the orientation in world space. The relative coordinates in relation to the view position are small enough to be represented by floats. The error in the float conversion is linear to the distance from the viewer and will disappear in the projection. =20 > -----Original Message----- > From: gdalgorithms-list-bounces@... > [mailto:gdalgorithms-list-bounces@...] On Behalf Of > George van Venrooij > Sent: donderdag 1 maart 2007 16:00 > To: Game Development Algorithms > Subject: Re: [Algorithms] Huge world, little precision >=20 > This is only true for objects whose size does not cause precision > problems. > Unfortunately, planetary bodies do tend to have such sizes. See my > original > post. At least, that's what I think... If I'm wrong about this, please > explain, it would save me a lot of trouble :-) >=20 > George >=20 >=20 > ----- Original Message ----- > From: "John Ratcliff" > To: "'Game Development Algorithms'" > > Sent: Thursday, March 01, 2007 15:44 > Subject: Re: [Algorithms] Huge world, little precision >=20 >=20 > > Dude, you do not have to transform the vertices! You only have to > > transform > > the translation component of the transform (not the rotation component)! > > When you build the matrix to send to the shader, just modify the > > translation > > component to be relative to the camera position. > > > > Also, I don't quite understand this conversation about high precision > > rotations. Rotations are always in object space, often represented as > > quaternion's which are normalized rotation values and, with these, > normal > > float precision is just fine. The only issue is the giant translation > > component which, with a minor joggle to your object-to-world transform > can > > be easily corrected. > > > > John > > >=20 >=20 > ------------------------------------------------------------------------ - > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the chance to share > your > opinions on IT & business topics through brief surveys-and earn cash > http://www.techsay.com/default.php?page=3Djoin.php&p=3Dsourceforge&CID=3D= DEVDE V > _______________________________________________ > GDAlgorithms-list mailing list > GDAlgorithms-list@... > https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list > Archives: > http://sourceforge.net/mailarchive/forum.php?forum_id=3D6188 ```