Hello. I was wondering if someone could help me out with a small problem I'm having. I am creating a candy bag and wrapping graphics on it. Sounds simple enough, right? Well, I'm not really all that familiar with vertex modeling, so I am building it as a spline model. Should work, but it's throwing things off a bit. When I apply the texture shader that I have created to the spline object, it seems to be stretching the graphics a little too much. ie. the name gets squashed, the curved line flattens in spots, etc. (By the way, the undulations are created by a noise bump map in the same texture shader.) If you can see in the supplied images (top bag is a photo and bottom is the model obviously), the graphics in the shader keep stretching too much here and there. Anyone have any thoughts on how to do this better or any other way? Thanks in advance!

 Oh, here's the spline view of the bag.

You could always convert the spline object to the vertex modeler and mess with the UV Mapping.  Sometimes I get results that look a bit better if you do the initial model without the ripples and wrinkles then apply the shader.  After it's applied, try going back into the model room and adding the wrinkles.  Like I said, it sometimes works for me.

 Hi Bookem,

This is one of those things about the spline modeler that is both a blessing and a curse. This time, it's a curse.

The bezier handles on the envelope/sweep path do more than stretch and smooth the object. Their use also does the same thing to the UV map. There are two ways to fix this: 1) distort your texture map to match/oppose the mapping distortion. 2) Convert the spline model into a vertex model, open the UV mapping function in the vertex editor and modify the UV mesh to remove the distortion.

Mark

I would use flat (planar) mapping, in case that hasn't been suggested yet.
use a folded plane as the model.  skip the spline thing.  when they manufacture the bag,
they may just use one sheet of plastic that's heat-welded at both ends and one side.

 Hey all. Thanks for all the good advice. I'm going to try these, but may be a little confused about some of them. 

1. When you say UV mapping in the vertex editor do you mean the texture room. Or is this something that I'm gonna have to play around with for a bit to figure out. (Like most applications)

2. Not sure what a folded plane is. Unless I'm folding it in the spline modeler. :) Can you explain?

Really, I'm not too amateurish at this. I have been with this program since it was Raydream Studio so feel free to give me all you got. I just have never worked my way into the vertex part of the program and just moved to Carrara about 8 months ago. ($$) Okay, so maybe a little amateurish compared to some of you, but I work alone and don't really have anyone to knock ideas back and forth with. Believe me, I'd love to know more about it. Just hard on my own, that's all.

Mark, distorting the polys on the UV map--haven't tried that yet--going to give it a try--Mark, you may have to stand by for a load of questions if I can't figure it out  

Folded plane thing--hmm need to try that--- Nancy, I may need your help too if I can't figure it out--Jan

this is one way to fold the plane.  of course, there will be texture stretching anywhere that polygons are deformed or enlarged.  that's why it might be necessary to reshape it in a way that doesn't alter polygon shape or size (e.g. fold or bend) to avoid said stretching.  like if ya bulge it out in the centre, then it hasta pull in the sides to keep all the polygons the same size.

If you've got the bag modeled already, I'd second Ms. Nancy's first suggestion of using projection mapping. Should be in your shader channels thingy with the other options of parametric and spherical. Might seem a bit hacky compared to proper UV mapping, but if you don't need to do the opposite side, it should work just fine.

Might need to put a touch of reflective in the shader somewhere too, to get that shiny mylar-plastic look.

---

Barbequed Pixels?

Your friendly neighborhood Wings3D nut.
Also feel free to browse my freebies at ShareCG.
There might be something worth downloading.

Or combine the two;  go into the UV room and apply a new planar map, put on a reference texture (I use a checkerboard) and tweak until it looks flat to the actual shape.

A more advanced technique some Poser content creators have used is to actually deform your mesh until it is flat, map it properly, then reverse the deformation.   Probably wouldn't be great technique on this bag, tho....I'd go with planar-and-tweak.

A last trick for some new model; UV map it when it is still a simple shape, then detail it using only tools that don't corrupt the UV map.  Can be dicey, but when it works is wonderful.