UV mapping help

wwwluckyro · Mar 25, 2007

UV mapping help

Hey! I'm totally new to Cheetah 3D. Have been trying tutorials from antialias.me.uk and it helped me a lot.

I'm trying to make a carrot (sounds easy, huh?) after successfully making a banana (see image attached).

The problem is with UV mapping. I can't get the "Unwrap UV" command to work. I don't know what to select exactly. I get really weird effects. If I use "Automatic Seams", it works, but not how I want (see image). It's just too complex.

Can anyone please explain how to use this or where can I find some information? I'd like to see for Cheetah 3D, not general for all 3D apps.

I've been watching the gallery all morning and I can see that people do impressive stuff with Cheetah 3D. Seems to be a really powerful application.

fused · Mar 25, 2007

Hi,
The sceret to good uv mapping is seam selection. The seam is where Cheetah unfolds your object and flattens it. Auto seaming is very good in Cheetah but it can over complicate things at times. The carrot should be very similar to the banana when selecting the right seam.

Andrew

wwwluckyro · Mar 25, 2007

yay

Hmm . . so I managed to do something after using the command "Toggle Seam". I forgot from the tutorial about it . . What does it do? I understood what toggle Crease does (i guess), but i'm confused on what toggle seam does.

Yeah I managed to do now. See image. Is it possible to separate my cylinder in just on face to paint. It acts really wierd when I jump from one side to the other.

wwwluckyro · Mar 25, 2007

heelp

I tried doing the carrot again, but I still have problems with UV mapping. Can you explain me why is this happening after I press Unwrap? is my object too complex?

novolume · Mar 26, 2007

Really bizzarely, although I understand how unwrapping uv and seams work, sometimes when I try and unwrap uv of a very simple object with a single seam cutting right through it I get very strange results like shown above aswell.

fused · Mar 26, 2007

I might be wrong but if you've converted a parametric object into an editable polygon then it should inherite basic uv coordinates so a uv tag is not required. I may be wrong though.

Andrew

frank beckmann · Mar 26, 2007

Hi Andrew.
I never would think you´re wrong.
I just build this object and try to understand what went wrong. Toggle the seams and got the same weird stuff. Began again. Put in the uv-tag, toggle the seams and hoppla here´s the unfolded mesh by surprise.
You have already much more experience on this like I have - so I missed something.
I have to check this. Thanx.
Frank

fused · Mar 26, 2007

wwwluckyro said:
I tried doing the carrot again, but I still have problems with UV mapping. Can you explain me why is this happening after I press Unwrap? is my object too complex?

This is a weird one. You should be able to make a parametric cylinder, make it editable, select a seam and hit unwrap uv. Let me think about it.

I never would think you´re wrong.

Thanks Frank, but my recent attempts to help have proven wrong.

Andrew

fused · Mar 26, 2007

Ok, even stranger. I can produce the same effect if I transform the geometry after I've made it editable (e.g. scaling it). However, if I delete one face and try unwrap uv it works correctly and if I fill the hole of the deleted polygon and unwrap uv again it still works. I must be missing something somewhere?

Andrew

novolume · Mar 26, 2007

Everytime I've tried it in the past it seems a little tempremental, in a lot of cases I've resorted to creating the object again which usually works. But as a rank amateur its more than likely something I'm doing/not doing that's causing the problems - if anyone works it out it would br greatly appreciated

frank beckmann · Mar 26, 2007

I got it now.

First I will clean up the thread.
Hi.
So I have to confess. It´s much easier than I expected.
At first one should try something very simple and unwrap a box for example. So make one, make it editable, go to the UV-editing layout. Now find the edges you want to be cut by Cheeath3d during it´s unwrapping process in the 3D view.
All you have to do now is to go "selection-> toggle seam", make a right click into the UV editor window and say: "unwrap UV". That´s it really.
Do you need any further instruction?
Let us know.

With kindest regards
Frank
I made a carrott again and it works perfectly, but don´t forget to "toggle seam".

bugaboo · Mar 26, 2007

Can't you just make a spline and then drag it into the lathe? Its like the Apple example. For fun I made a carrot. Though, it looks quite glossy. I'm a noob too.

Though, I am wondering is there a default light? How do you turn the default light off? When I look in the object browser tab, initially, there are no lights -- one would assume the scene would be black when I render?

novolume · Mar 26, 2007

There's a light attached to the camera. If you click on the camera you can switch it off in the properties panel.

bugaboo · Mar 26, 2007

Behold, there is a light in the camera! Good. Thats convenient but not obvious for the noob.

I think the automatic seams => unwrap features really helps with the uv placement. I like that.

Hmm, not sure the visibility button is working correctly. I assume when I uncheck visible that object is suppose to disappear? The row is highlighted blue on the lathe yet visibility button is not working. I copied my lathe object. Then converted it to a polygon object. Then made the original invisible but the checkbox seems to have no effect. I get a little paranoid about converting to polygons because its difficult to go back.

novolume · Mar 26, 2007

If you want to make an object invisible, you click on the m icon next to it in the object browser window, you can then make objects either visible in the editor or renderer by checking the appropriate boxes in the properties window.

wwwluckyro · Mar 27, 2007

not that helpful

bugaboo,
what you did is a simple carrot. what i did is a much more realistic one. I first made a cilinder then manipulated it a lot. it's not regular at all.

yeah, frank beckmann, i follow each step and i still get the weird effect.

so i tried it again:
create a simpler cilinder (picture 1), destroy it (picture 2), loop select + toogle seam + unwrap (picture 3), paint + subdivision (picture 4)

i guess it worked on a simpler object. I'll do my complex carrot again and see if it works this time. It kinda sucks I can't save in the demo, but it's better than nothing.

i'll get back here

frank beckmann · Mar 27, 2007

Ho IK now eh

Hi OK, now: here we go.
Make a carrot as realistic as you might like.
Go to UV editor layout. In the 3D view choose your edges via loop. I made polygons at the end and tip of the carrot with inner extrude and one cut from side to side that just one single loop selection is necessary. So now follow closely:

A: Select this loop-> toggle seam
B: change to polygon mode via toolbar and select all polygons (command+a) !!
C: Go to UV editor and say "Unwrap UV". That´s it.
D: Now you can via "group select" and "transform" arrange the two halves to fit the map.

With kindest regards
Frank

wwwluckyro · Mar 27, 2007

yaay

thanks for the jas file. . it's helpful to analize it.

step B - i didn't know selecting all helps
step D - i didn't know i can move those things. I was so sad each time they were off the white square (map)

hey it helped me a lot. I'll do the carrot again when I have time and I'll post back here. Thanks :tongue:

novolume · Mar 27, 2007

Sounds like you had exactly the same problems as me. I didn't realise that you needed to select all and also, like you say, I didn't know you could transform the unwrapped UV.

Great stuff Frank.

capnchunky · Mar 27, 2007

The reason for selecting is that the Unwrap command only unwraps the selected geometry. It might seem like a hassle, but there are lots of times when working on more complex models where you only want to re-Unwrap a small part of the whole model, so you just have to select that one part.

UV mapping help

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