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benclark
03-25-2006, 06:50 PM
Hi

I have been under the impression since I started using Zbrush that if a model was going to be normal mapped then you had to layout each piece of the mesh seperately - no mirroring UVs and no sharing texture space.

Is this true? I was looking at the maps for this model that was posted up here recently and there are plenty of mirrored uvs and the normal maps look brilliant.

http://www.t3h-v.com/folio/corum.html

So why are there loads of posts everywhere saying that you cant do this? I'm a bit confused!

ArchangelTalon
03-25-2006, 06:57 PM
It depends on the engine.

Most engines that support normal mapping can compensate for having two halves of a model covered by the same normal map.

You may find you have problems when you render out the normal map to start with, however, as it tries to apply two normal maps to the same area of texture space.

benclark
03-25-2006, 07:43 PM
Thanks for the help.

Where in Glasgow are you studying?

ArchangelTalon
03-25-2006, 09:11 PM
Heh, I'm actually studying at University of Teesside in Middlesbrough.

I still call Glasgow home, though :P

glynnsmith
03-26-2006, 05:02 AM
Yeah. I had a bit of trouble with symmetrying the UV's in the past. It turned the flipped half inside out.

Heh, I'm actually studying at University of Teesside in Middlesbrough.

I still call Glasgow home, though :P

Whehey. Another one. What year/course?

ArchangelTalon
03-26-2006, 12:44 PM
Computer Games Art, first year.

Dull as a wet Tuesday :P

glynnsmith
03-26-2006, 02:36 PM
:D ACE! That must be one of the new courses. Pretty much all of the games art modules used to be under the blanket course of Computer Games Design, which is the bag I'm in.

How're you finding it?

G

benclark
03-26-2006, 04:09 PM
Mr Smith, that is a handsome moustache

ximage
03-26-2006, 04:46 PM
hey looks like u got a bit of a UK only thread going here, woot woot. i was wondering about that normal thing aswell, but then again i haven't made a games model yet, all the stuff iv done is hi-res, when i graduate i wanna get in to the games side, suppose i should have done a games course instead. hehe
just thought id say hi ne way!

sweeney

ArchangelTalon
03-26-2006, 05:17 PM
:D ACE! That must be one of the new courses. Pretty much all of the games art modules used to be under the blanket course of Computer Games Design, which is the bag I'm in.

How're you finding it?

G
Aye, I think this is only the second year it's been run.

It's pretty boring so far as I already know all we're being taught this year. Hopefully it'll pick up next year and we get to be a bit more creative. Still, it affords lots of time for working and drinking, which I'm not complaining about.


And not being allowed intersecting geometry in our models is driving me up the wall XD

glynnsmith
03-26-2006, 05:49 PM
Mr Smith, that is a handsome moustache

Hey! I wasn't offering my drawn on lip hair for critique!! :P :D

It's pretty boring so far as I already know all we're being taught this year. Hopefully it'll pick up next year and we get to be a bit more creative. Still, it affords lots of time for working and drinking, which I'm not complaining about.

And not being allowed intersecting geometry in our models is driving me up the wall XD

Yup. The first year drags a bit. I mean, who would apply for a game art course and not know basic functions of photoshop? You CAN speed it up with getting drunk a lot and trashing the uni housing :D

Haha. The intersecting geometry thing. I had so many arguements with my tutor about that. It's a good way to learn good modelling practice, but it is a bit unrealistic/outdated. It does get better though, so hang in there ;)

You mind me adding you on msn? I feel a bit guilty hijacking Alchemist101's thread :argh:

G

ArchangelTalon
03-26-2006, 06:17 PM
Sure thing.



Apologies Alchemist101, have you had any success with normal mapping yet?

SHEPEIRO
03-27-2006, 07:56 AM
when i was deciding what course to go on at uni (bout 6 years ago) i talked to the course leader thjat i was interested in and decided i knew more than him about games art design, which i probably did, so i decided to stick with creativity and do a Fine Art course, :shrug: , anway i regret it now as i fell behind in my knowledge while the courses seem to have got quite good. BUT NOT ALLOWING INTERSECTING GEOMETRY, sorry but that just doesnt make sense, even if you want to improve your modelling skills, surely you should do it with a mind for the industry your entering.

sorry for hijack- the thing about flipping uvs with normals (outside of game engines compatibility) is that you can do it but you want to avoid seams down the centre of the model. so flip arms and legs but do the head chest and torso completely. put the seams in sensible places like where clothing meets

benclark
03-27-2006, 11:30 AM
I have had some good results but I have always taken the time to map out the UVs for each arm and leg seperately. Its worked for me so far so I'll stick with it instead of pissing around with a new method.

MarkD
03-27-2006, 02:14 PM
Instead of rendering both sides at the same time can you render one side to get the normal map? For example you have arms that share the same texture space, delete one of the arms when you render the normal and add it back in after? I'm not sure this would work but I'm pretty sure I saw this method being done before...

requiem2d
03-27-2006, 03:18 PM
Thanks for the info guys, wasn't aware it was that much of an issue. Could you manually use a blur brush on the seam via photoshop though I guess?

MDA
03-28-2006, 03:46 PM
You do need support for flipped UVs on the engine side which is another issue but there is an easy hack to check your work in the view port.




- Duplicate your normal map.

- Invert the GREEN channel (flipping Left to Right)

- Now apply this normal map only to the flipped UVs




Hope this helps.

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