Home Register Arcade Gallery Chatroom Members Search Today's Posts Mark Forums Read Log In
Go Back   Inside: SereneScreen Fan Forum > SereneScreen Products > Marine Aquarium 3 for Windows > Marine Aquarium 2 for Windows Archive
Notices

Reply
 
Thread Tools
Old 12-22-2007, 02:26 PM   #1
Submariner
Registered
 
Submariner's Avatar
 
Join Date: Sep 2003
3 Highscores

Location: Connecticut
Posts: 901
3d fish

This question is for Jim. When I use wire mode on MA, DA, or any of the digifish aquariums i see the the fish are made with triangles. I have read that
quads are best for subsurfing and animation, so why is everyone using triangles not quad polys?

SUB
Submariner is offline   Reply With Quote
Old 12-22-2007, 05:41 PM   #2
Jim Sachs
Developer
 
Jim Sachs's Avatar
 
Join Date: Dec 2000

Location: Southern Oregon
Posts: 9,768
Quads can get non-planar and render improperly. Triangles can't.
Jim Sachs
Creator of SereneScreen Aquarium
Jim Sachs is offline   Reply With Quote
Old 12-24-2007, 09:40 AM   #3
Submariner
Registered
 
Submariner's Avatar
 
Join Date: Sep 2003
3 Highscores

Location: Connecticut
Posts: 901
I did not know that. Is that true of traditional animation as well or just the tweening animation?


SUB
Submariner is offline   Reply With Quote
Old 12-24-2007, 12:05 PM   #4
Jim Sachs
Developer
 
Jim Sachs's Avatar
 
Join Date: Dec 2000

Location: Southern Oregon
Posts: 9,768
All 3D objects, whether they are used in an animation or in rendering a static scene, are subject to non-planar errors if they use polygons with more than 3 sides. It's worse in animation, because the vertices are moving, and part of the polygon can suddenly flip to facing the other way, disappear completely, or not display its texture properly.

The problem is simple: if you create a square, then move one of its points perpendicular to the other 3 a little distance (or a lot), the square is non-planar. Or move the point so that any of the outside angles is acute (less than 90 degrees). Now you're in even worse trouble, because 3D programs have no definition for how to render this object. By definition, a triangle cannot be non-planar, because whenever you move one of the points, the whole surface tilts accordingly.

Most (if not all) rendering engines automatically convert all polygons into triangles anyway. If you do it yourself, you have control over which vertices are used to form the triangles, which can make a big difference in how the object gets rendered.
Jim Sachs
Creator of SereneScreen Aquarium
Jim Sachs is offline   Reply With Quote
Reply
Go Back   Inside: SereneScreen Fan Forum > SereneScreen Products > Marine Aquarium 3 for Windows > Marine Aquarium 2 for Windows Archive



Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -6. The time now is 12:32 PM.


Powered by vBulletin®
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.