Joel
0
Subdivision
Learning how to use subdivision has been a slow process, even though my single-shot renders are simple compared to, say, animated characters’ facial expressions. In particular, overall smooth compound curves that incorporate small curved details (e.g. car body with air ducts). I am starting this thread in the Tutorials sub-forum because it’s general, not a solution to a specific problem. (Yes, I know the topic of subdivision has come up a few times before.) Subdivision is so fundamental, so powerful, but far from intuitive for 3D beginners, even if they have lots of 2D experience. I hope experienced users will add posts with related basic advice for beginners, to give them a running start. What would help are posts that are general, that can be applied to a car, human, or toaster, like example jas files, step-by-step doo-dads, animated gifs, links to previous C3D Forum subdivision posts or other 3D sites, including YouTube and Vimeo. Or how to combine subdivision with a script or another modifier. Define terms as you go, like n-gon, Iterations, Constraint. Show how any aspiring designer can invest 99 dollars and get up to speed quickly and start producing professional-quality 3D work. And have free, 24-7 access to the internationally-acclaimed Cheetah 3D Forum.
I am still struggling with the process, but in my search for online help I came across some resources that would be of value to many C3D users:
Macmonkey recently posted a link to a site promoting a box modeling primer, which looks like a good deal:
https://www.cheetah3d.com/forum/showthread.php?t=12846
The book’s author also posted an excellent PDF of a basic introduction to subdivision modeling:
(“Go With the Flow” at bottom): http://pushingpoints.com/v2/got-wires/
Basic illustration of stepping-down to decrease polys (or stepping up to add detail):
https://pixelandpoly.com/img/step-down-guide.png
Simplified guide to basic subdivision dos and don’ts:
http://www.rbandeira.com/nfos/01_gr...hp?PHPSESSID=0b2a679609e663fa3d67e2fd294cef9e
Tricky parts: Note “Edge Loop Transitions” and “Triangles and N-Gons”:
http://graphics.pixar.com/opensubdiv/docs/mod_notes.html
Zoohead’s thread — making realistic cars:
https://www.cheetah3d.com/forum/showthread.php?t=10474
What I’ve learned so far:
Use all quads (see links for triangle and n-gon exceptions)
Hide unavoidable triangles and n-gons in flat areas or on the back side (no visible “pinching” mesh distortions)
Use the fewest possible “container” edges to define subdivided surfaces.
Toggle Subdivide modifier (and Symmetry modifier) on/off in Object Browser (don’t collapse yet)
Check progress with test renders using a black and white Wireframe material
Use 4-point triangles to “step down” two rows to one (to reduce polygons and mesh complexity)
Use 4-point triangles to “step up” one row to two (to add detailed areas)
“Flow” loops, no dead ends or excessive parallel loops
Use a tight parallel edge instead of a crease for realism
Make the box model larger than the default Box so Optimize doesn’t weld distinct points
Use Blueprint and Ortho-view Bezier lines as visual guides
What I am still figuring out:
(See above links)
Search keywords:
Box model, Quad, Crease, Loop, 4-point triangle, Step-down, Flow, Catmull-Clark
Learning how to use subdivision has been a slow process, even though my single-shot renders are simple compared to, say, animated characters’ facial expressions. In particular, overall smooth compound curves that incorporate small curved details (e.g. car body with air ducts). I am starting this thread in the Tutorials sub-forum because it’s general, not a solution to a specific problem. (Yes, I know the topic of subdivision has come up a few times before.) Subdivision is so fundamental, so powerful, but far from intuitive for 3D beginners, even if they have lots of 2D experience. I hope experienced users will add posts with related basic advice for beginners, to give them a running start. What would help are posts that are general, that can be applied to a car, human, or toaster, like example jas files, step-by-step doo-dads, animated gifs, links to previous C3D Forum subdivision posts or other 3D sites, including YouTube and Vimeo. Or how to combine subdivision with a script or another modifier. Define terms as you go, like n-gon, Iterations, Constraint. Show how any aspiring designer can invest 99 dollars and get up to speed quickly and start producing professional-quality 3D work. And have free, 24-7 access to the internationally-acclaimed Cheetah 3D Forum.
I am still struggling with the process, but in my search for online help I came across some resources that would be of value to many C3D users:
Macmonkey recently posted a link to a site promoting a box modeling primer, which looks like a good deal:
https://www.cheetah3d.com/forum/showthread.php?t=12846
The book’s author also posted an excellent PDF of a basic introduction to subdivision modeling:
(“Go With the Flow” at bottom): http://pushingpoints.com/v2/got-wires/
Basic illustration of stepping-down to decrease polys (or stepping up to add detail):
https://pixelandpoly.com/img/step-down-guide.png
Simplified guide to basic subdivision dos and don’ts:
http://www.rbandeira.com/nfos/01_gr...hp?PHPSESSID=0b2a679609e663fa3d67e2fd294cef9e
Tricky parts: Note “Edge Loop Transitions” and “Triangles and N-Gons”:
http://graphics.pixar.com/opensubdiv/docs/mod_notes.html
Zoohead’s thread — making realistic cars:
https://www.cheetah3d.com/forum/showthread.php?t=10474
What I’ve learned so far:
Use all quads (see links for triangle and n-gon exceptions)
Hide unavoidable triangles and n-gons in flat areas or on the back side (no visible “pinching” mesh distortions)
Use the fewest possible “container” edges to define subdivided surfaces.
Toggle Subdivide modifier (and Symmetry modifier) on/off in Object Browser (don’t collapse yet)
Check progress with test renders using a black and white Wireframe material
Use 4-point triangles to “step down” two rows to one (to reduce polygons and mesh complexity)
Use 4-point triangles to “step up” one row to two (to add detailed areas)
“Flow” loops, no dead ends or excessive parallel loops
Use a tight parallel edge instead of a crease for realism
Make the box model larger than the default Box so Optimize doesn’t weld distinct points
Use Blueprint and Ortho-view Bezier lines as visual guides
What I am still figuring out:
(See above links)
Search keywords:
Box model, Quad, Crease, Loop, 4-point triangle, Step-down, Flow, Catmull-Clark