Unwrappng UV’s? To create texture?

[Adam Trachtenberg]

Unwrapping UVs is the (or a) correct term. In this case it should be pretty easy since the model probably conforms pretty well to the preset cylindrical mapping type. What you would do is set the texture tag to use cylindrical mapping and then right-click on the tag and select “generate UV coordinates” from the pop-up menu.

At that point you’ll want to export a wireframe texture for the texture artist to use as a placement guide. To do that, follow these steps:

* Choose the BP UV layout from the layouts dropdown menu;
* Select your object, and from the Tools menu, run the Paint Set Up Wizard;
* Uncheck “Recalculate UVs” and click Next;
* Choose which material channels you wnat, their base color, and the texture size;
* Click “Finish”.

That creates your material, assigns it the object, and makes the material active in BodyPaint. Next, select the paintbrush tool and set the color to black. Then run the Layer>Create UV Mesh Layer command and save the texture (File>Save Texture).

If you check the texture in PS you’ll see that you have separate layers for each material channel you selected, plus a alpha layer on top showing the UV mesh.

If your model doesn’t fit the cylindrical shape all that well it gets a bit more involved.

[Robyn Rhodes]

Hi Adam,

I have a question.

I have uploaded my project here…

files.me.com/mr27/srl5bm

which should have the UV Mesh Layer texture, which I generated based on the instructions you gave. I also included a PDF of what I expected to get from the Create UV Mesh Layer command.

The way I was thinking about it, I thought that C4D would export a shape within a square which when filled with the appropriately deformed artwork of the yogurt label, would deform perfectly on the yogurt container. I am confused by the aspect of the Mesh Layer generated. Also I’m not sure I understand why you are allowed to dictate individually the height and width of your Mesh layer since it should have a fixed aspect based on the aspect of the polygon selection.

I have saved a polygon selection which the yogurt label would go on.

By the way this isn’t the yogurt container. It’s just quick shape generated for the purposes of understanding this technique.

Thanks very much for you input.

Robyn

I’m only half the thing I say I am, the other half are me.

[Adam Trachtenberg]

The download link isn’t working for some reason. You can attack file here.

[Robyn Rhodes]

Here it is Adam.

1173_hyawatha.zip

I’m only half the thing I say I am, the other half are me.

[Adam Trachtenberg]

Okay, got the file, and a number of things:

1. I didn’t realize you were modeling it with a Lathe NURBS. When you use spline-based NURBS they generate very good UVs automatically, so all you have to do is make the object editable and skip to the setup wizard part of what I posted before;

2. Generally speaking the automatic (and nurbs) UVs try to maximize texture space, using a square canvas. Actually UV tiles are always square. If you are using a non-square texture you have to compensate by using bigger bitmaps;

3. As a consequence you’ll either have to scale the UVs manually in BP, or else compensate by using the Length X/Y parameters in the texture tag. Because you want a paintable UV map, you’d want to scale the UVs before generating the UV wireframe. You can do that in BP by selecting all the UVs and then using the BP>Non-uniform Scale tool. You want the UV polygons to have the same width/height ratio as the actual polygons. As a guide you might want to draw a circle or square in the base color channel and look at the shape as you’re scaling the UVs. When you get the relative width/height to your likeing, run the “create UV layer” command.

hth