Unwraping an extruded cylinder…

Sorry about not getting back to you I’ve been changing my service provider, what a nightmare, in the end I had to purchase a new PC!!! <!– s:) –><img src="{SMILIES_PATH}/icon_e_smile.gif" alt="" title="Smile" /><!– s:) –>
My old one was way past it’s best.

So back to your problem, yes if you want to paint on a lot of detail you must unwrap the object.
If your going to just unwrap one side of the boiler, the easiest way is to build just half the boiler, unwrap it, clone it and flip it along it’s x axis, then weld the two halves back together. That’s how I would do it.
Even this has it’s problems though, as what you paint on one side appears on both sides.

Anyway glad your getting somewhere atb last.

Bazza

All,

It’s always just getting started with texturing a model that’s a bit like a trip to the dentist… We could definitely use a little more functionality with the unwrap options available in 3DC… Things like move a group of points together – align points – flip the orientation – etc etc etc…

I have an extruded beveled cylinder – the boiler on my locomotive… What is the best way to unwrap this shape ???

Should I try quartering each part of the cylinder and pasting them together on a single texture file ??? Because of the bevel – the pieces will not fit nicely together…

Should I just half split the entire shape down the middle as I did in the attached example ??? I think I would try stretching this shape across the entire width of the BMP… Also – I get a white line on the edge where the two halves meet – can’t seem to get rid of it…

Should I try to distribute the sections on the top and bottom that are closely space from perspective ???

Any help – always appreciated…

Regards,
Scott

Unwraping a tapered cylinder with 3DC isn’t that easy, as you’ve found out. Hopefully things will improve when Richard gets round to looking at the unwrap feature again.

The problem is that whichever way you do it you will end up with joint lines, the trick is, to try to reduce the number of joint lines to as low as possible, ie one joint line which can be positioned along the underside of the boiler.
If you unwrap the cylinder as you have done by quartering or halving the cylider when you unwap this will give you many of these unsightly joint lines.
And this is likely to be the reason for the white lines you can see.
I bet you are using a white background to the texture and this can show up between these joint lines.
Try changing the background colour to say black or red and see if the lines change colour.
One way around this problem is to increase the painting area for each section of the unwrap areas by two maybe three pixels..see if this corrects the problem.

So how do you create an unwrap of a cylinder with just one joint line?
Well, unfortunately with 3DC you can’t, you need a dedicated unwraping tool such as Ultimate Unwrap 3D.
This allows you to stitch the seams of the unwrap back together so you end up with just one joint line.
In fact UU3D allows you to unwrap a cylinder with just one mouse click.
If it were a tapered cylinder you would need to adjust the verts/points to correct the taper.
The downside to all this is that you need to export the boiler from 3DC, import it into UU3D then when the unwrap is complete import it back into 3DC.

All this isn’t what you wanted to hear is it, I can just see you groaning…hehehe, but it’s the only way at the moment if you want a perfect unwrap.

Do you need to unwrap the boiler, have you tried applying a texture with a cylinder wrap and adjusting it to get the best possible effect. This works for me in most cases, unless the taper is severe, then the only answere is the unwrap.
[img:e43urmpk]http&#58;//amabilis&#46;com/forumattachments/a/tpc/f/9606089974/m/64210899241[/img:e43urmpk]
<!– m –><a class="postlink" href="http://amabilis.com/forumattachments…089974/m/64210899241">http://amabilis.com/forumattachments&#8230; … 4210899241</a><!– m –>
.
The smokebox was unwraped but the texture applied to the tapered boiler was just a 256×256 texture applied with the fill tool, then scaled as required.
I know this isn’t perfect but I think the trick is to achieve an overall effect with the textures, much as an artist would do in a painting.
It works for me anyway.

See Attchement…

Top left….The boiler texture
Bottom left….The Firebox texture
Right……..The Smokebox, cab sides and buffer unwrap.

Hope some of this helps.

Hi Bazza,

THANK YOU for the very detailed response… I’ll go through it in great detail tonight when I get home…

I’ve got about three nights wasted trying to figure out the best way to do this…

I even downloaded the UU3D demo… Haven’t quite figured out how to use it yet… You just gave me a big clue – though – in that I should be exporting individual parts and not the entire model !!!

I’m sure I’ll have more later…

Enjoy your weekend !!!
<!– s:) –><img src="{SMILIES_PATH}/icon_e_smile.gif" alt="" title="Smile" /><!– s:) –>

Regards,
Scott

I don’t think their is a best way really, it seems to vary from loco to loco.
I try to avoid unwraping boilers if possible due to the large amount of UV map space they take up. Also you will need a very large UV map if you want to unwrap the boiler in one piece with just a single joint line.
However the unwrap will allow you to paint more accurate detail, but again only if the map is large enough.

If I can get away with applying a boiler texture of say 256×256, scaling it as required, I save oodles of memory and don’t have to do the unwrap. <!– s:) –><img src="{SMILIES_PATH}/icon_e_smile.gif" alt="" title="Smile" /><!– s:) –>

Yes I have to export individual parts, unwrap them then import back into 3DC, I can still have all the parts on just one map if required.

Bazza

Hi Bazza,

Man – this is really like pulling teeth…
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I did this once before – but – with a less complex shape… Maybe I should just purchase the UU3D and give it a go…

I attached my shape – should I try to do it differently to aid my unwrap in 3DC – or – would UU3D handle this OK ???

LOL – once I get this first piece licked the rest should fall into place – right…

Oh Richard – if you are listening…
A few additions to [b:bdt6wbx3]UNWRAP[/b:bdt6wbx3]:

[b:bdt6wbx3]- move a group of points together
– align points
– distribute points
– flip the orientation
– scale on the X or Y plane only (stretch)
– more granular control of positioning
– a bigger screen for the UNWRAP operation
[/b:bdt6wbx3]

Pleeeaaaase !!!

Regards,
Scott

Is this the boiler section from your Lehigh and Hudson River 4-8-2 Heavy Mountain loco?
This shouldn’t be to difficult to unwrap with UU3D.
I’m just going to eat so I’ll get back to you in a short while, can we see the boiler texture you want to apply, maybe you can do this with the fill tool in 3DC.
Later…

Bazza

Hi Bazza…

Enjoy your meal – sir…
<!– s:) –><img src="{SMILIES_PATH}/icon_e_smile.gif" alt="" title="Smile" /><!– s:) –>

Yes – this is my LandHR boiler… I haven’t made the texture yet… Maybe I should – and – try it your way… Maybe it will give me some fresh perspective…

If you recall – I built a Prairie a few years back and I have been trying to remember how I did that one… It had a taper as well just not as complex… I’ll attach the texture I used there for an example… It has been reduced and compressed to upload here… Originally it was a 3MB 1024×1024 TIF file… I’m trying to recall why I used TIFF now – I think the details came out better…

I did get it to come out distortion free with all the details on the model… I don’t think I used flood fill – but – I did paint both complete sides to avoid the seam issue… Just got to clear the cob webs out of my head !!!
<!– s:) –><img src="{SMILIES_PATH}/icon_e_smile.gif" alt="" title="Smile" /><!– s:) –>

Thanks for your help and patience !!!
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Regards,
Scott

OBTW: I tried to load the DEMO UU3D on my PC – it fails when I try to run the actual program… Just my luck 1 step forward – 2 back – hehehehe… ‘Side by Side configuration is incorrect’ ???

OK…leave it with me, I’ve just tried applying one of my loco boiler textures with the fill and brush tools it doesn’t look to bad..I’ll try it with your texture see how it looks.

I’ll get back to you…maybe tommorrow.

Bazza

Hi Bazza…

Some luck – I found the original PSP…
It doesn’t look like I did anything special on the taper but it does look like I unwrapped it… What’s with the diagonal line ???

I’ll attach the image…

Does this shed any light on how I did it ???

LOL…

Regards,
Scott

THANKS Buddy !!!

No rush…

Regards,
Scott

It looks as though you may have unwraped the boiler by selecting say three or four faces at a time and laying these out side by side. the diagonal line is were a point has gone astray when you’ve draged them around.

If your using Vista, this may cause a problem with UU3D but I’m sure there are some comments for vista users on their site.

Bazza

All,

OK – I made a little more progess… One of my big issues – is that I FORGOT you can actually crop the area of the texture you want to unwrap too… When I was trying to do the cylinder – I was starting out using the entire texture which was way out of proportion… I’m a little closer now…

So here is where I am at…

– I selected my texture
– I cropped a reasonable area for the shape
– I quartered the cylinder selecting faces
– I used the unwrap operation
– I saved the unwrap
– The unwrap marked my BMP with the selection

BUT

When I look at the shape now – I just have that checkerboard pattern appearing on the shape where my BMP image should appear ???

What am I missing ???
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[img:14n8jvlp]http&#58;//img&#46;photobucket&#46;com/albums/v304/scottb613/TS/Image1&#46;jpg[/img:14n8jvlp]

Thanks,
Scott

OK – more progress…

Apply Material to Selection

Got it – although tedious – seems I have to reselect all the surfaces after the unwrap operation… As long as it works…
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Mirror same texture on other side ???

Now – how do I do I get the other half of the cylinder to use the same texture mappings as the first ??? Seems we need to mirror the texture somehow – as when you unwrap the shape – the mappings go in the opposite direction… The flip texture on the material pallet doesn’t seem to work… Do I have to manually manipulate the points to match up with all the points I unwrapped on the first half ???

My unwrap is attached – on the right track ???

[img:2hcrhtda]http&#58;//img&#46;photobucket&#46;com/albums/v304/scottb613/TS/Image1-1&#46;jpg[/img:2hcrhtda]

Regards,
Scott

I used a slightly different technique about 3/4 of the way down this page:
[img:h5zlva9q]http&#58;//steam4me&#46;railpage&#46;org&#46;au/trainsim/tutorials/Steam3DC/part_7&#46;htm[/img:h5zlva9q]
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