Join Thanassis Pozantzis for an in-depth discussion in this video Unwrapping a cube, part of Up and Running with Bodypaint in CINEMA 4D.
- Mookie has a new-found talent. He likes to hula hoop but this is totally irrelevant from what we are trying to do here, so bye, bye Mookie. Let's make a cube and make it editable. In order to unwrap this successfully, we need to follow the steps we saw in the previous video. Pinning, cutting, unwrapping. Currently, if we go to the UV Edit and drag our UV map on the texture here, you will see that all the polygons are stacked.
So if I use my selection tool and select them and then my move tool and move them around, I'm moving everything around. I can always go and select individual polygons and I will pull them out. As you can see, they are stacked. I'm not gonna continue. It's six squares stacked on top of each other. Undo. Undo. Undo. And this is our default cubic mapping. So what I need to do and follow the steps of the previous video is the following: Let me go to my 3-D polygons and select the bottom polygon.
This is the immovable part of the box and everything else is going to be unwrapped around it. Let me go to my Standard layout and command click here and turn that polygon into a point selection. These four are going to be the pin points. Select, Set Selection, to save the selection on the object. And let's call this, "pin." You can use any name you want but "pin" is a very descriptive of what we are trying to do.
Step number two, edges. And let's define which edges we are going to cut. Live Selection Tool. I'm going to select this one, this one, this one. And this one. So these are gonna be cut and I'm gonna select this one. And this one. So these two sides are going to unfold and only this one. I want these two to stay connected. So these two polygons, I want them to stay connected so they can unfold this way.
And I have my cutting edges. I need to de-select the point selection. Go to Select and Set Selection. Let's name this "cuts." So we have our "pin," these four points. And we have our "cuts." These edges. Let's go now to our UV Edit layout. I need to tell CINEMA 4D which of these polygons we wish to unfold, or unwrap.
I will select everything. So UV Polygon mode, put my mouse over here, and press command + a, or control + a on the PC. And I've selected all my UV polygons. The next step is very important. In order to set that pin polygon, we need to do something which is part of the procedure. I need to view my box from the bottom.
The best way to do that is to go to one of my orthographic views. I'm going to go to my top-view and change my camera to Bottom. Now, we are looking from the bottom up. We are looking upwards. I will maximize this view, zoom in, and the next step is I want an initial UV unwrap based on this view. In order to do that, I need to go to the UV Mapping tab, Projection sub-tab.
And click on Frontal. This will create a UV map based on the camera view we see here and as you can see, there is a correlation. Had I chosen to go to another view, if I press Frontal, I will get this UV map. So let me go back to my bottom-view. Press Frontal and there you go. There is a reason we do that because now we are actually looking at the correct side, the outer-side of the bottom polygon.
Let's do the unwrapping now. Go to the Relax UV tab. Let me move this so we can see better what we are doing. And I need to do the following: I need to activate the Pin Point Selection, activate the Use Tag. As you can see, I've done that before and it remembers the name. This is just a coincidence. I need to drag this tag into here. It's the same name. I have been practicing, to be honest. Activate the Cut Selected Edges, as you can see here.
Turn on the Use Tag then drag the cuts in here. Normally, you will see empty link boxes and if you drag these in here, you will get the appropriate tags. So the "pin" in the Pin Point Selection and the "cut" in the Cuts. The next thing I need to do is Apply. And look at this, it kept the bottom polygon where it is, it detected the cuts from the tag.
So these were cut all the way around. And it unfolded using the LSCM algorithm. There are two algorithms here, LSCM and ABF. There's nothing particular between the two. One is supposed to be better than the other in certain cases. This is somewhere where you need to experiment. There's not much you can do in terms of learning which is best in each case. You may end up just using one or experiment between them. For complex 3-D unwrapping, you may need to fiddle around with these sometimes, but that's another story.
And there you go. We have an unwrapping of a cube. One thing I want to mention is that because it's overshooting, it's outside our UV tile, we can go to what is called a UV Command and do Fit UV to Canvas. It will fit all the selected UV polygons and scale them so that they fit as a group inside the UV tile. More on this later, but there you go.
You have your first unwrapped cube.
Author Thanassis Pozantzis covers a wide set of techniques, from material projections and generating UV maps to UV unwrapping, both for hard surface models (such as packaging and mechanical objects) to organic models (including humans, monsters, and animals). Start here to learn how to incorporate BodyPaint into your production workflow.
- Everything you need to know about material projections
- Creating and editing UV maps
- Setting up a project in the BodyPaint interface
- Unwrapping UVs, from cubes to bananas
- Hard-surface model unwrapping
- Organic model unwrapping