Maya for 3D Printing - Rapid Prototyping
In this course we're going to look at something a little different, creating technically accurate 3D printed parts.
# 1 15-03-2006 , 02:01 PM
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5+ and 3 sided polys

Hi,

just a simple question out of curiosity. Why avoid 5 and 3 sided polys while modeling? The 5+ ones I can see the reason, but wht#s wrong with 3 sided ones. As you will heve to use them ocasionally. Does it have to do with texturing? Or maybe animating your model. Even though you can triangulate and its fine to animate afterwards.

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# 2 15-03-2006 , 02:06 PM
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Re: 5+ and 3 sided polys

Originally posted by farbtopf
Hi,

just a simple question out of curiosity. Why avoid 5 and 3 sided polys while modeling? The 5+ ones I can see the reason, but wht#s wrong with 3 sided ones. As you will heve to use them ocasionally. Does it have to do with texturing? Or maybe animating your model. Even though you can triangulate and its fine to animate afterwards.

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theres no real reason to avoid them really. they work fine for me in most cases.


only reason for maya is when u convert a poly with a non-quad face into a subD it wouldnt render in MR [until maya 5 i think] now u can just use the subD aprrox tool and it renders quad non-quads no problem.user added image

# 3 15-03-2006 , 02:30 PM
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Ok,

why should I then spend hours adding lines to my model, complicating geometry just to get rid of two tri's.

doesn't make sense.user added image

# 4 15-03-2006 , 02:37 PM
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From what I've read you should maintain as proper topology as possible, using 4 almost square sides, as it can seriously affect the way light is reflected and simply makes it easier to texture/alter geometry etc. It also can cause major probs with animation if your geometry is not 4 sided and smooth flowing.


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# 5 15-03-2006 , 02:42 PM
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Originally posted by j5ive
From what I've read you should maintain as proper topology as possible, using 4 almost square sides, as it can seriously affect the way light is reflected and simply makes it easier to texture/alter geometry etc. It also can cause major probs with animation if your geometry is not 4 sided and smooth flowing.

u have proof or examples of such cases?

# 6 15-03-2006 , 02:47 PM
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Examples of where I read it yes, Books 'Creating the Art of the Game' by Andrew Ward I think and Game Character Development.


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# 7 15-03-2006 , 04:23 PM
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I've looked at a lot of meshes that have been made at my work, and 3-sided tris aren't totally avoided, especially when you are modelling highly realistic stuff that needs bevelled edges and the likes. However, meshes that will be subdivided and characters are always kept to quads (as much as is possible), but it doesn't matter when your making a purely polygonal model. 5 or more sides should be avoided though. Sometimes its just not feasible to create a lot more geometry just to get rid of a few tris.

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# 8 15-03-2006 , 05:40 PM
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J5ive: if i recall right, all game models are triangulated, so im not sure why a game book would be against tris..
tris work in some places, in other places they dont, same goes for n-gons

# 9 15-03-2006 , 07:46 PM
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so I don't nmeed to spend hours thinking how to split my polys just to wipe out tris:attn: Sounds good to me. I was just wondering because in all the vid tutorials I've seen so far the instructors emphazise a lot on tidying up until all the tris are gone.
From what you guys said it sounds a bit like an oldschool habbit to be on the safe side.

# 10 16-03-2006 , 09:27 AM
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Vlad: Game models are normally made as quads then converted either manually or automated into tris, or they can be made from scratch straight as tris, but it isn't really good work flow having lots of both. I am stating what I read from books I am currently reading, other than me scan the pages I suggest you get them yourself and have a read through.

Though, like you said using tris to add geometry at times is the most effective way. I suppose it depends what this guys model is for as to whether he could get away with slack edge loops and stable polys.

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# 11 16-03-2006 , 11:25 PM
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Is just using triangulate or quadrangulate good enough? Or is it better to manually change them?

# 12 17-03-2006 , 12:53 AM
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From all the books i've read they ALWAYS go on the quad route,

However they do then go on to say you "Should try to keep into quads for ease of animation and conversion into other programs"

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