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# 1 23-02-2011 , 01:43 PM
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Subdivision Problem

Hi guys

I posted quite recently about a subdivision error, which I sorted out eventually but now I have another , I have been modelling a car and when I come to duplicate the half to make the main body of the car I have some problems. I duplicate the body over, combine, and merge vertices along the edges but when I come to subdivide I get an error.

I have upped the settings in the Polygon to Subdiv option window, looked for and deleted rogue points and tried to create edge loops. I really am at a loss now, I think that there are still problems in the mesh but can't find them.

The scene file is below so if you guys could have a look and give me any advice it would be great.

https://hotfile.com/dl/106951853/cf50..._Testl.mb.html

Thanks
Paul

# 2 23-02-2011 , 03:22 PM
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I have to ask, is there a reason you're moving from Poly's to Sub D's at this stage (if even at all)?

# 3 23-02-2011 , 03:25 PM
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Well there is quite a bit more detail on another maya file and I just wanted to check that the subdivide looked right when I duplicated the car over.

# 4 23-02-2011 , 03:49 PM
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Ahh ok I see.

However the first car I made was in sub-D's and I found it to be a pain in the ass to be honest (especially in comparison to other techniques). I ended up bringing it to poly's which alleviated the majority of the issues I had. Plus when you come to render Sub-Ds will more often than not take considerably longer to render (been there too). Agreed sub D's have "some" advantages but as a general rule if I do use them it will be in the early stages and i'll convert from them not too them.

Also I would suggest splitting up your car panels, bumpers, fenders etc, in reality car panels are separate geometry, model them like there are built whilst maintaining edge flow throughout. The majority of car render issues are caused by overlapping geometry caused by making the majority out of one piece (and overlapping UV's, but that's a different issue all together).

In summary
If your working with Poly's now, I would stick with them.

# 5 23-02-2011 , 03:55 PM
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Thanks for the reply mate, I did seperate some of the panels which is why there aren't any door and bonnit, the only reason i didn't seperate the rest was because when I did before the panels then didnt fit together as well as they had done before.

I only know of subdividing for smoothing and no other way to be honest, any other ways you can suggest when I have finished the modelling stage?

# 6 23-02-2011 , 04:26 PM
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When modelling with Poly's (well any tool really), the trick is to keep it as low resolution as possible, and you can switch between preview modes (by pressing "1","2","3") at any point, but it makes for good practice to model at level "1", and use "3" for checking periodically.

When you are ready to render you can smooth your mesh
1) Polygon Menu > Mesh > Smooth
2) Modify > Convert > Smooth Mesh Preview ("3") to poly's

the problem being if your model isn't low res to begin with you could end up with an awful lot of geometry.

If your scene is going to have a considerable amount of polys, you can at this point look into proxy models (low poly versions used as place-holders), and creating attributes/scripts to turn on/off your smooth (as to only have is on at render time)

you can also play with the "Normals" if your getting some hard edges or simply to tweak the look. a good place to start with the normals
1) Normals > Set To Face over entire object
2) followed by "Normals > Average Normals",
secondly by changing how edges are perceived by the renderer these can also help to adjust problem areas
1) Normals > soften edge

# 7 23-02-2011 , 04:28 PM
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Honestly mate thats great, really had no idea you could have the polygon preview as a render option, I only thought subdivision was the option. Ill have a go tonight seperating the pieces of the car again then do all that you said

Thanks Alot man

Paul

# 8 23-02-2011 , 04:41 PM
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yeah no worries buddy, hope that points you in the right direction at least.

Ash

# 9 23-02-2011 , 04:53 PM
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the scene as it is right now works just fine (mirroring and merging that is). only problem is - the verts in the middle are not snapped to your ZY plane. so it leaves a gap in the middle. if you move them and snap them they will do what you want - hope thats what you meant ???
user added image)

you do seem to have a whole lot of mess though from converting back and forth from poly to subd and back.

hope that helps

oh and plus what ash says

# 10 23-02-2011 , 05:22 PM
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Yeah thanks duck, the problem was that I was converting to SubDiv's which wouldn't work but using Ash's way of using the smooth its fine. Ive since merged the verts and everything seems good user added image

# 11 23-02-2011 , 05:52 PM
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no problem - I remember having a mel script on a button (loooong time ago) that would perform a polygon smooth and then next to it a undo button - a quick preview of smooth w/o having to deal with the stupid smooth poly cage when it was new and still messy.

# 12 04-03-2011 , 01:41 PM
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no problem - I remember having a mel script on a button (loooong time ago) that would perform a polygon smooth and then next to it a undo button - a quick preview of smooth w/o having to deal with the stupid smooth poly cage when it was new and still messy.

How do I undo the Convert > Smooht Mesh Preview to Polygons in Post Render MEL script?
I'm tried a lot of stuff but for some reason it didn't work....

Thanks in advance
by the way, yes I'm a piece of wood in MEL scipts!

# 13 06-03-2011 , 03:41 PM
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How do I undo the Convert > Smooht Mesh Preview to Polygons in Post Render MEL script?
I'm tried a lot of stuff but for some reason it didn't work....

Thanks in advance
by the way, yes I'm a piece of wood in MEL scipts!

i didn't undo it post render. it was just a Mesh->Smooth and a "undo" afterwards to it. just for preview while modeling real quick. you don't have to convert it to render the smooth mesh preview. you could even leave it not smoothed in viewport and still have it render smooth if you check as in the picture while you are in 1,2 or 3 mode.

p.s.: i usually duplicate my model, mirror and attach it and smooth it then smooth preview it whenever i want a test render. and if i don't like it i delete the duplicate and go back to modifying the original. i know i am weird, but that is me

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Last edited by BabyDuck; 06-03-2011 at 03:43 PM.
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