Path: chuka.playstation.co.uk!news From: Alex Herbert Newsgroups: scee.yaroze.programming.2d_graphics Subject: Re: Animating sprites Date: Thu, 14 May 1998 23:36:25 +0000 Organization: PlayStation Net Yaroze (SCEE) Lines: 42 Message-ID: <355B71E9.57E9BFBF@ndirect.co.uk> References: <01bd7ac4$e4eda480$7397989e@antonio.lightwork> Reply-To: aherbert@ndirect.co.uk NNTP-Posting-Host: dialin2-54.ndirect.co.uk Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 4.04 [en] (Win95; I) To: Martin Swaine Martin Swaine wrote: > Hi, > > Can anyone help please? > > I am developing a demo in which a sprite is moved along a spline curve. The > co-ordinates are precalculated so the program only needs to keep redrawing > the sprite at these positions. > > To keep the thing fast the distance between each consecutive instance of > the sprite is quite large. The problem is I am seeing a trail of several > dimmer copies behind the current sprite. > > I have reduced the brightness of the object in case the screen phospher was > not decaying fast enough. I am using the standard sequence of > Vsync/Drawsync and other drawing primitives. > > Has anyone else ever seen this? What might I be doing wrong? > > Thanks, > Martin I've just been thinking about this one. Does your sprite have a lot of black (STP bit set) at the edges? Have you got the semi-trancparency mode switched on? If so then it sounds like you may not be clearing the screen properly, and overlaying transparent sprites on eachother, thus making the previous sprite darker (with semi-transparent black). Are you clearing the screen correctly. Are you double buffering correctly? It may not be the answer, but this would cause this type of effect. Herbs