problem with air vents on poly model

# 1 09-07-2010 , 03:08 AM

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hello. I'm trying to do some poly modeling for a pickup truck. I want to put in some vents on the hood and I'm having problems. The idea is to model in poly and then "convert smoothmesh preview to polygons." I'm trying to subdivide a face and then extrude the subdivisions down to create the slots of the vents, but i can't keep the corners of the face square. It doesn't matter how many edge loops i put in, whenver i hit 3, the corners collapse. So instead of getting linear slots, i get curved slots. I assume i must be going about this wrong. Do i have to put in edgeloops for the entire truck body to get these vents? that seems like it would add a lot of complexity where i don't really need nor want it.
thanks guys

reference image:
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poly model:
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poly model with smoothing (3 key):
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xxx

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# 2 09-07-2010 , 07:00 AM

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You need to adjust your topology to fit, try to keep it all quads

"No pressure, no diamonds" Thomas Carlyle

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# 3 09-07-2010 , 10:12 AM

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You might want to reduce the size of your posted pics mate..they will delete them.

Is this what you were trying to achieve?? I am probably wrong

cheers bullet

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bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes

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# 4 09-07-2010 , 02:58 PM

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as Gster said it needs be quads to get it smooth well but it would add a lot of topology to the model so you might be better off making a rectangular cut out (hole) for the vent and modeling the vent as seperate geo.

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# 5 10-07-2010 , 10:52 PM

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thank you for all the responses. Sorry about the large images. Sorry also if I'm out of my depth with this. I'm just doing this as a learning exercize.

@bullet, yes that is more or less what i'm trying to create. (thanks for posting the example, it was helpful in getting the vent holes to look right).

So if i extract the face and turn it into a vent, everything is fine, but when i try to re-attatch it is where I run into problems. It looks fine in poly mode, but when I turn on smoothing, it becomes apparent that I'm trying to fit a rectangle into a circular hole. I understand that this is also going to create non-4-sided faces, which is not good.

Does this mean that I'm going to have to create edge loops to line up with all the edges for the vent holes? or...

@jsprogg - you're saying that I might keep the vent as separate geometry? Does that mean the corners of the vent would line up with the rest of the body, but that it would be a separate object? I don't understand how I could get a continuously smooth surface with that method.

poly view mode
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smooth-shaded mode
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attempt to attatch vent to body
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# 6 11-07-2010 , 12:49 AM

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First I would staighten some of the edges up..as per my pic.

You can leave it as a seperate geo easily...just extrude the edges down a couple of wee times and whack a few edge loops in...it will then square off nicely and the components will work.

OR you arent snapping and merging verts properly?? IF you have any polyline meeting the area you have cutout..you need a corresponding one on the 2nd piece for it to snap. You cant have free/lazy verts around..it wont work.

If you have extracted correctly then thos verts from the body polyline should still be there..if not put some wee ones in with polysplit.

chhers bullet

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bullet1968

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# 7 11-07-2010 , 12:59 AM

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Here is an image re-size vid too

https://dl.dropbox.com/u/4090628/image_resize.wmv

cheers bullet

bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes

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# 8 11-07-2010 , 01:47 AM

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as Bullet has said you can extrude it down and add a loop or two to keep it tight.
to Make any corner stay tight when smoothed add a split close to either side of the corner ..the closer it is the tighter it will stay, but try to end the split so as it stays quads.

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# 9 14-07-2010 , 05:40 AM

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What you could try depending on what version of Maya you are running is extrude your quads down a little from the original one piece mesh in poly mode, then select all the edges around the holes and use the crease tool to keep everything from goint circular.

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problem with air vents on poly model

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