Many objects have a revolving nature that would benefit from seemless textures and/or textures that span completely around a surface of the 3D model. In this tutorial, we will look into what is involved in detailing a common, graphite pencil.
The modeling portion will be done in the Vertex Modeler (VM). After the assigning the UV coordornates, you will learn how to export a 2D bitmap of the UV lines so that you can paint your own textures in a 2D program of your choice. The act of painting the image maps is not covered in the scope of this tutorial.
The below textures are my solution to painting on the UV bitmaps. However, because there will be slight differences in modeling and UV work between one person to another, these textures will probably not align up to your work by default. We will cover the mantipulation of UV's for exact placement in a later tutorial.
You will learn more about the process of texture mapping, if you create your own 2D bitmaps after you get the exported image instead of trying to use the examples below
If you would like to view how I set up the texture maps into a shader, please download the below .cbr files for the version of Carrara that you are using.
Start Carrara, if it is not already running. Create a new empty scene. Insert a Vertex Model (VM) object by clicking on the icon and dragging it into the workspace.
Create a Cylinder in the VM with a ten (10) setting for object definition. Using the scale tool or the scale mantipulator to stretch the cylinder to be the full length of the pencil minus the tip. Select the top edge loop. Turn off the crease characteristic of the segments (segments that are creased appear in blue instead of grey). Select the top face and extrude it into a point. Continue with a couple, very small extrusions to round out the point. Select the edge loop where you removed the crease and re-apply the crease. Your model should look like Figure 9.
Figure 9.
In the properties panal, click on the UV Map tab (in C3, the tab is called UV Mapper) followed by the UV Editor button.
In the UV Editor, click on the Projection Tab. Select the Cylindrical type from the drop-down menu. Click on the Z axis arrow. Finally, click on the Apply button. Your UV Editor should look something like as in Figure 10.
Figure 10.
With all the points selected in red, select the scale tool and reduce the vertical height of the UVs by a small amount. Because the detail is extreme at the tip and to ensure that the UV's are in a good position to paint on (with my texture maps, the point is at the top of the map and the eraser is at the bottom), we will want to Zoom in and inspect the top portion of the UV layout. Figure 11 shows the extreme close-up of the UVs that form the tip of my pencil.
Figure 11.
The UV's are now set up correctly. However, we will need a 2D image of the UV lines to paint on. We do this by clicking on the Display tab. Click on the large white square in the bottom left to select that option. Then click on the Background Color color chip and change the color to a pure white. Your options should look like Figure 12.
Figure 12.
Click on the Export... button. A dialog box will appear asking you what filename to save as and as to what type of file you want. Pick the settings that best work with your image editing software.
Ideally, you will then use this new 2D image to paint your own textures. If you do not wish to create your own maps at this time, you can use my sample textures (supplied at the top of this web-page). However, my texture will probably not align up with your pencil model due to small differences in modeling. Because of this, you will need to adjust the UV's in the editor after you assign the texture-map powered shader, but this will not be covered for this part of the UV Collection Series.
Click on OK at the bottom of the UV Editor to accept the UV layouts.
Setting up the shader is very similar to that of the first tutorial of UV collection. With each channel that you painting a map for, apply that texture map to them. Figure 13 displays my personal solution to painting and assigning the texture maps.
Figure 13.
If you painted your own texture maps, then you can go back to the VM or Assembly Room and render a preview of your texture mapped pencil. My pencil can be seen in Figure 14.
Furthermore, if you would like to compare my file with yours, please download the following .car file (made in C5P and may not work in other versions):
I've also converted the file format into the wavefront's .obj format for older versions of Carrara (and or other programs), however the texturing probablly should be re-applied from the .cbr file near the top of this tutorial. The zipped file includes the .obj (1), .mtl (1), and texture maps (3).
If you used my sample texture maps, you will probably need to re-enter the VM and then the UV Editor. The color channel's texture map of the applied shader should be visible behind the UV lines. You will need to manually adjust the UVs to match the texture map. More info on this aspect will be presented in a later tutorial, however it can be good practice for you to attempt this on your own.
Figure 14.
In Figure 15, I used the completed pencil model from this tutorial in a small physics render. This is just one possibility that you can play with on your own.
Figure 15.
