Le Mercredi 23 Novembre 2005 10:14, Andreas Neumann a écrit : > > You are right, a pity I have to lose the opacity 'effect' (this > > part of svg > > > was part of a bigger one wit stuff that went under the rect). > > no, you don't, you can use group-opacity instead of individual > opacity. > > I would also suggest that you slightly overlap the rects by > increasing the width and height attribute a little bit, to avoid > rendering artefacts. By using group opacity instead of individual > opacity you don't see the overlapping effect on the individual > rectangles. > > Have a look at http://www.carto.net/neumann/temp/rects.svg for an > example on overlapping and group opacity.
For the record, the correct URL is http://www.carto.net/neumann/temp/rect.svg I'll have to play with that and see what I get out of either or both of these suggestions (overlapping rects and/or group opacity), but this does sound promizing, thanks for that. > If you need an algorithm to calculate gray values according to > height values in the terrain and a given light direction, I can send > you pointers - that's a well-known problem in GIS and a very simple > formula. If you read French, my reference on this so far is this: http://www.utopisland.com/stf/pro_projets-estompage-index.php this guy presents a couple of approaches of that problem that basically all use a simple matrix product, which can apparently be done pretty easily in T-SQL (I use MSSQL). I haven't played with this at all, since my main focus so far was to fine tune my terrain generation algorithm, but this is next on the list so probably I'll take your word and bug you about it if I get no success studying this. My main concern with that problem of relief lighting though, is that each of my maps have about 4k pixels, and I suspect this may not be enough to render anything good looking. Furthermore, I am not willing to split these square pixels into vertices (I'm not too familiar with this, but I think that would normally be the thing to do to get something nice), as this would add to the SVG rendering engine burden, and they already do not perform too well (either ASV3 or FF1.5) with that many objects. So all in all, I am wondering if doing anything more sophisticated than "one altitude => one opacity" will be really worth the pain. What do you think? Your answer will tell me how much time I'll spend on that part ;-) > ANdreas I appreciate your help very much. Cheers, Sylvain ___________________________________________________________________________ Appel audio GRATUIT partout dans le monde avec le nouveau Yahoo! Messenger Téléchargez cette version sur http://fr.messenger.yahoo.com ------------------------ Yahoo! Groups Sponsor --------------------~--> Get fast access to your favorite Yahoo! Groups. Make Yahoo! your home page http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/1U_rlB/TM --------------------------------------------------------------------~-> ----- To unsubscribe send a message to: [EMAIL PROTECTED] -or- visit http://groups.yahoo.com/group/svg-developers and click "edit my membership" ---- Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/svg-developers/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
