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View Full Version : Chicken and egg question? Model to UV or UV to model?



raw-m
07-23-2017, 02:19 AM
I've been supplied some artwork that is handily prepped for print, so it's various boxes unwrapped and flat.

Would you model the box first then UV? Quick to model and subd but UVing is a pain in LW. The artwork needs to be precisely placed with no stretching so eyeballing into place is best avoided.

Create the box flat to the UV? Although really easy to create all the sides initially, gets really fiddly if you need to add slices to subd. A morph is created and sides are rotated into place but dealing with overlaps can again be fiddly.

Wondering what approach you take here?

gar26lw
07-23-2017, 02:46 AM
Yeah, I might well just model the box with the print work as a guide, flat. Planar map the print work first, so helping with the model process, then, when done, just create uvs based off of that planar map with texture guide.

Then I'd create a morph and fold up the box.

You could just model the box and uv it too but I think it might actually be easier and quicker to do it the "real world" way.

daforum
07-23-2017, 03:12 AM
Can you Planar UV the model flat and then rotate the sides as a morph (essentially folding and assembling the box as you would in real-world?)

Ah just read gar26lw's post - basically same thing i suggested.

Would like to know how you did this in the end ( if we are allowed to see the work of course?)

erikals
07-23-2017, 04:22 AM
i don't find UVing in LW all that hard honestly, it's tedious no matter what app one use.

but yes, Egg first, then Chicken >

http://freedesignfile.com/upload/2016/12/Perfume-box-packaging-template-vectors-material-07.jpg

raw-m
07-23-2017, 05:06 AM
Thanks for the response! I'm giving the UV flat approach a go - MGImagesToPlanes makes setup amazingly easy! But, if I create cut marks and then change their position to tighten up edges, for instance, my UV is distorted and I'd have to re-UV(?).

erikals
07-23-2017, 05:22 AM
if I create cut marks
yes, you'd have to reUV, however, you could select an area, then UV map only that area over again.

any post-modeling means reUVing. inevitable unfortunately  :)

gar26lw
07-23-2017, 06:03 AM
If you keep your image to planes mesh in a layer, then cut out/up the uv mesh version, with a morph map on it that dictates the final folded box, you can unmorph, tighten edges and then remake the uv map via planar projection, with the images to planes mesh in the foreground, to maintain the same projection bounds. Make sense?

erikals
07-23-2017, 06:26 AM
yep, and if you wrap/animate the box using bones/weights instead these issues are basically non-issues.

if so, create skelegons in Modeler
(better than Layout Bones as Skelegons can be snapped to points)

raw-m
07-23-2017, 06:50 AM
Thanks all, feeling a lot more confident now!

I was getting to obsessed will upsetting the UV too early on. I'm doing the UVing and folding into place first and basically using that as a reference while a model the packaging as I need, with folds, overlaps, depth, nice edges etc, then I'll backwards engineer it by unfolding and adding a final UV.

Still interesting in other approaches, though!

jasonwestmas
07-23-2017, 09:45 AM
I would model each section individually (and flat) using the template (black lines/creases). Planar map each section unwelded and then weld the geometry together after its been mapped. Assemble the pieces together into box form after that. Done for the most part with some minor tweaks.

raw-m
07-23-2017, 10:07 AM
Having spent the afternoon battling with Los UV tools, I'm warming to that idea Jason! Won't you loose the Planer map when you start assembling/rotating pieces into place?

jeric_synergy
07-23-2017, 10:18 AM
I would model each section individually (and flat) using the template (black lines/creases). Planar map each section unwelded and then weld the geometry together after its been mapped. Assemble the pieces together into box form after that. Done for the most part with some minor tweaks.

+1. I've done this before, and if you have scanned a real box, very like the prepped artwork in question here, it's pretty straightforeword. (Bones, weight maps, etc.) Pour moi, the only issues were getting realistic bends at the edges of the box: it's trivially easy to get an unrealistically crisp/sharp edge, but getting a nice cardboard fold was quite a bit harder. In geometry, at least.

I suspect there's some shader out there that would dull CGI style 90 corners to a nice fold in a mere click or two.
+++++++++

Having spent the afternoon battling with Los UV tools, I'm warming to that idea Jason! Won't you loose the Planer map when you start assembling/rotating pieces into place?

All the folding occurs in Layout, not Modeler, so it's like any texture that's been deformed with Bones.

raw-m
07-23-2017, 11:09 AM
Ah, thanks for the explainer Jeric, that makes much more sense! I've been experimenting with a bone rig on a 2 point poly chain and meta-linking the object to it - works surprisingly well without getting bogged down in falloffs and weight maps!

Danner
07-23-2017, 06:03 PM
If the quads don't match the exact same shape in the UV you'll have distortion. Sometimes you'll have to un-weld a section, re map and put it back in place to regain proportion to remove distortion. Keep in mind that every quad will ultimately be displayed as a pair of triangles, and that is the basic limitation on why you can't adjust the shape of a quad and have the UV follow the edges. If you still need the edges of the quad to follow the image lines after you modify the paralelism (is that a word?) then subdividing the quad will help but it will still distort somewhat.

137459

erikals
07-23-2017, 06:31 PM
just a preview of how you could go about it...


https://www.youtube.com/watch?v=2IwE53H-9uA


also see, Rotate skelegons tool
https://www.youtube.com/watch?v=XWgUCnxMfKI

raw-m
07-24-2017, 01:38 AM
Thanks so much for everyone's input, lots of great tips in there! Very much appreciate your time in doing that erikals, I'm always a sucker for workflow tips, too. I'll let you know how I get on further down the road.

erikals
07-24-2017, 02:06 AM
happy to help Mark :)
especially nice since you help others so much with video tutorials yourself. :)

Mark Warner >
https://www.youtube.com/channel/UCJUynRdT9wndRTdc7s9NwyA/videos

:king:

jeric_synergy
07-24-2017, 09:43 PM
Besides what erikals demo'd-- I didn't watch the complete thing-- but as an ultimate backup and to prevent shooting yourself in the foot, you could of course use an endomorph after the UV process is complete.

It's the ultimate backup, because you've still got the original geometry in the base.

jasonwestmas
07-26-2017, 07:46 PM
Having spent the afternoon battling with Los UV tools, I'm warming to that idea Jason! Won't you loose the Planer map when you start assembling/rotating pieces into place?

No I don't think assembling the box will distort the map if you model your creases correctly. You just have to fold the flaps accurately after you map it. You may have to tweak your UVs slightly. That usually is the case with all models.

probiner
07-27-2017, 08:28 AM
I've done a bit of these, so I would say:
- Make a quad frame that matches the print file and in the surface editor do a planar projection of the texture. Also setup a viewport backdrop using it.
- Now you can model with the artwork both as back drop and texture on your model without worrying about UVs.
- Do a UV Map using the initial quad as the bounding box.
- Fold a copy and where it doesn't fold well come back to the original and adjust.

If you use some Layout deformation to do the folding, you don't even need a UV, just use the Planar projection, otherwise, keep it simple.

Cheers

raw-m
07-28-2017, 01:50 AM
Cheers Probiner. I've settled on a similar workflow, deforming in Layout with minimal bones. I have 3rd Powers Weight Paint and this is such an easy process now! It'll create maps for each bone in Layout and from then on it's simple to change/assign values. Tweaking the model in Layout would be nice though!