PDA

View Full Version : Subdivision order? What does it MEAN?!



Psycho Zo
03-24-2008, 08:39 PM
Hi, I dunno how much of a n00b question this is, but what the hey!

I'm always fiddling with my subdivision order in layout, with endomorphs Lightwave loves it set to last. Just today though I was wondering... what does this even mean!?! I've just been scrolling through the list of options finding what looks right when choosing, but I don't actually know what the technical or mathematical difference is between the choices. Why do my morph targets work best set to last? What is the difference between sudividing first and last anyway? 0_o

Just googled it and tried looking it up in my Lightwave books, but nothing seems to go into that detail.

Enlighten me oh wise users!

Initium Thoth
03-24-2008, 09:24 PM
Download the web based help package to read in detail(search for subdivision, and chose the item with Object Geometry tab), but the reasoning is that depending on how many deformations take place on your mesh, First or Last will have these deformations take place on the low poly model with Last or the fully meshed high poly model with First.

SplineGod
03-24-2008, 10:36 PM
Basically it has to do with order of operation. Do you want the SubD cage to subdivide first then morph or morph first then Subdivide?
Last means that the low rez cage will be morphed or deformed first with less geometry and then be subdivided at rendertime with more geometry.

Weetos
03-25-2008, 02:28 AM
Hi Larry

I always wondered what would be the benefit of setting it to anything else than 'Last' ? Are there some particular situations where you need to set it to 'First' or something else ?

Sorry for the thread hijiacking, guys, I'm taking advantage of the fact Larry answered the question, and see if I can have a little more details on the matter :angel:

Drocket
03-25-2008, 03:49 AM
William Vaughan mentions this in his "Introduction to Endomorphs, Morph Mixer and Open GL Sliders" tutorial on the NewTek web site, I know I just watched it :)

Larry's description is spot on (as you would expect :)).

Here for the complete list of training material:
http://www.newtek.com/lightwave/training.php?t=77002

Here for the endomorph link:
ftp://ftp.newtek.com/multimedia/movies/w3dw/Endo.mov

Drocket.

Surrealist.
03-25-2008, 04:43 AM
Hi Larry

I always wondered what would be the benefit of setting it to anything else than 'Last' ? Are there some particular situations where you need to set it to 'First' or something else ?

Sorry for the thread hijiacking, guys, I'm taking advantage of the fact Larry answered the question, and see if I can have a little more details on the matter :angel:


There are some situations where you won't be able to use last.

Check this out (http://www.newtek.com/forums/showthread.php?t=78993&highlight=displacement).

Weetos
03-25-2008, 05:18 AM
There are some situations where you won't be able to use last.

Check this out (http://www.newtek.com/forums/showthread.php?t=78993&highlight=displacement).

Thanks Surrealist, this is really interesting - makes sense now :thumbsup:

Psycho Zo
03-25-2008, 07:51 PM
Hi Larry

I always wondered what would be the benefit of setting it to anything else than 'Last' ? Are there some particular situations where you need to set it to 'First' or something else ?

Sorry for the thread hijiacking, guys, I'm taking advantage of the fact Larry answered the question, and see if I can have a little more details on the matter :angel:

Ha ha... no this is where I was gonna go with this anyway... I often thought 'why is there even a choice'? Actually I often wonder about the whole relative/absolute choice in morph targets too when absolute will mess up when you use it. :S (Well when I use it anyway :P)

Just read through the other post where sub d is set to first and think I get the theory of what they are explaining, I think a lot of the more mathematical stuff escapes me sadly. I'm looking to improve my knowledge on that side of things.

Thanks for the response guys. :)

Surrealist.
03-26-2008, 12:29 AM
Weetos - your welcome. :)

And Psycho Zo, glad you got something out of it too. :)