Path: chuka.playstation.co.uk!news From: Developer Support Newsgroups: scee.yaroze.programming.3d_graphics Subject: Re: Hierarchic Objects Date: Mon, 11 Aug 1997 17:30:26 +0100 Organization: PlayStation Net Yaroze (SCEE) Lines: 54 Message-ID: <33EF3E22.2114@interactive.sony.com> References: <33EB50EF.7318@mintsauce.com> NNTP-Posting-Host: 194.203.13.10 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.01 (Win95; I) Simon Wood wrote: > > Hi > > I am having some problems achieving hierarchical objects. I want to > achive the effect shown on page 66 of the User Guide using multiple TMD > objects, so far I have failed miserably. I want the outer group to > control the overall path of the objects, and the individual objects to > 'twiddle' within that path. I want the path to be specified on the > outer group object and not have to specifiy it on any of the child > objects. I assume this is done with the super field of the > GsCOORDINATE2 structure. Yes; eg in a solar system the Sun might have it's own coordinate system, (ie its GsDOBJ2.super points to its own GsCOORD2 whose super is WORLD); the planets might have the Sun as their super, ie their GsDOBJ2 can either directly point at the Sun's COORD2, or can point at their own COORD2s, whose super's are the Sun's COORD2; and similarly for moons, satellites of moons, etc. At present I am using the function in the file > object.c supplied with the tuto?.c files. I am willing to move away > from using that file if it makes things easier. I would like to > understand the low-level solution as well as the object.c based > solution. Ultimately I will move away from object.c anyway, but at the > moment I am pressed for time on this project. > > I realise that this should be fairly and I am sure I am missing > something simple and fundamental; But I have not managed to find any > samples that do this and the documentation does not seem to address the > point beyond page 66 of the User Guide. > > Any hints, clues, sample code, references, websites etc. would be much > appreciated. > > Regards > > Simon Wood > Black Sheep Design > simon@mintsauce.com The SCEE samples and both use hierarchical coordinate systems; I think is probably easier to understand. The simplest case of hierarchy is like that in solar2: just get 3 objects and build a tree of three members with three levels. Try simple controller-driven motions to test it. This way you should get the hierarchy working very quickly. Lewis