This month, VFXWorld continues a series of six excerpts of the Course Technology book Maya Plugin Power, which will give VFXWorld readers to learn how to take advantage of the myriad of plugins available to Maya users.
There are a fun set of useful Maya plugins from a company called ticket01. One of these tools is called Seamour. It helps to create a variety of stitching effects on a surface. This beats the hell out of a bump map when real geometric detail is needed. Here is a look at creating seam stitching.
Check out Course Technology site for additional information and files.
You can certainly save a lot of time with this plugin compared to a weak workaround. SmartDuplicate is handy and gets the job done. It is simple, powerful, and supports the duplication of multiple instances with different object types all at the same time. Let’s look at another plugin from Ticket01 that has similar characteristics as Wire and SmartDuplicate but has a more narrow niche application. It’s called Seamour.
Stitching With Seamour
Seamour, which may or may not be the combination of the words seam and amour, or a love affair with seams, creates stitching geometry. This plugin performs a tiresome function that you rarely see modeled but is a nifty addition to a model, giving it a new level of realism. Let’s use Seamour to generate some stitchery.
On the companion DVD in the Chapter 9 folder is a scene called stitches_1.mb. The loaded file should look similar to Figure 1. A quick render will make it look like Figure 2. Installing Seamour is simple. Executing the installer program is easy and is no fuss. After installation, make sure the plugin is loaded and recognized by Maya. This can be done by going to the top of the screen in the Maya menus and selecting Window > Setting/Preferences > Plug-in Manager. Make sure that both the Loaded and Auto load boxes are selected next to Seamour.mll. There should now be a Ticket menu at the tope of the screen. If you have installed Wire and SmartDuplicate, they will be present in the Ticket menu as well.
[FIGURE 1] A mesh plane acts as a piece of cloth for stitching with Seamour. [FIGURE 2] A quick render of a plaid piece of cloth.
Seamour creates a shelf that is very helpful for accessing the tools. Your interface may not have the tool shelf open. This can be accomplished from the Maya menus. Select Display > UI Elements > Shelf, as shown in Figure 3. The Seamour shelf should appear.
Open the shelf to reveal the various Seamour tool icons, as shown in Figure 4.
Making a seam straight down the middle of our cloth is quite easy. It’s best to do this in wireframe mode in the top orthogonal view. Follow these steps for a quick and easy seam.
[FIGURE 3] Turning the Maya Tool Shelf on in the Maya user interface. [FIGURE 4] The Seamour icons with their functions listed below them.
- We need to create a curve based on some of the edges of the polygonal cloth object. Select the polygonal edges of the mesh right down the center of the cloth, as shown in Figure 5. To do this, select the wireframe mesh and press the F10 key. Drag a selection box around the middle edges. If you accidentally select unneeded edges, which is fairly easy to do, you can deselect them by holding the Ctrl key down and drawing a selection box around the offending edges. Selected edges can be hard to see, as they are usually the Maya default light orange color.
- The exaggerated edges selected and shown in Figure 5 must be made into a curve. This can be accomplished by clicking on the Create Curve from Selected Edges tool in the Seamour tool shelf (see Figure 4). The Outliner now lists a new curve node labeled edgeCurve, as shown in Figure 6.
[FIGURE 5] An exaggerated view of the edges needed to be selected to generate the edgeCurve. [FIGURE 6] The dark line represents the edgeCurve generated and is listed in the Outliner.
- For this example, we will create orthogonal stitching. These stitches are created by following the edge curve. This may be better viewed with smooth shading on and hardware texturing off. Select the edgeCurve node in the Outliner window and click on the Create Seam with Orthogonal Stitches icon in the Seamour tool shelf (this icon can be referenced in Figure 4). The direct results of this action are shown in Figure 7.
- A multitude of staple-shaped stitches have been replicated along the edge-Curve. They are currently too large and bulky for a realistic look. Let’s adjust them. In the Outliner window, select the seam1 node that has been created. Load the Attribute Editor for the seam1 node.
- Under the Yarn tab in the seam1 Attribute window, toggle the Relative Yarn scale box to off. This may make the seams jump in scale to unusable proportions. Set the Yarn Profile scale value to 0.025. This allows us to scale the profile of the yarn as we see fit. Also make sure that the Extrude Yarn toggle box is checked.
- These stitches look quite large. Let’s make them smaller. Under the Template tab in the seam1 Attribute window, change the Template Scale value to 0.15. The template is a staple-shaped curve that is generated by Seamour to give form to the individual stitches. Figure 8 shows how changing the Template Scale value alters the seams.
[FIGURE 7] Oversized seams now appear on the edgeCurve. [FIGURE 8] The seams start to take shape by scaling the template value down to size.
In Stitches
Seams in Seamour have a few basic components. The first is a user-designated or designed curve that can be made from polygon edges or that is drawn. The template defines the overall shape of the individual stitches, making them look similar to a staple. The yarn profile is the circular curve that is extruded over the template curve, creating the actual surface of each stitch. These components are tweaked in the Attribute Editor of the seam node to shape the stitching that suits your needs.
- Let’s create a few more stitches to tighten it up a bit. In the Seam tab of the Attribute menu, change the Stitches value to 70. This creates a tighter cluster of stitches plus an errant one. This is the first stitch in the series, so we can eliminate it by changing the value of Start with Stitch to 2 or, in other words, starting with the second stitch in the sequence.
- The stitching looks a bit crowded. Let’s bump the Yarn Profile to 0.09 and change the Template Scale to 0.084. Our stitchery should now look something like Figure 9.
- Finally, a few shaders are included in this scene file. The tan shader labeled phongE1SG can be found in the Multilister. Drag this shader onto your stitching geometry and render it. The nice uniform stitching is fairly convincing, as shown in Figures 10 and 11.
[FIGURE 9] Readjusting scales and the number of stitches makes a better-looking seam.
[FIGURE 10] A render of the stitches as geometry. [FIGURE 11] A closer look at the Seamour stitchery.
Mark Jennings Smith is a seasoned artist, animator and writer residing in Beverly Hills, CA. Smith has been fascinated by CG since 1972, when at age 10 a chance encounter with the first coin-op Pong changed his life. His interest in the entertainment field led Smith and a partner to establish Digital Drama in 1994, which focused on computer-generated imagery, animation, digital painting and special digital visual effects. Digital Drama designed the digital film effects and animation for companies such as Universal Pictures, Trimark Pictures, Fox Home Ent., HBO and Showtime. Smith has contributed to several books and magazines, including a chapter in Maya: Secrets of the Pros. He also created cover art for the book and a variety of other titles in the 3D arena. He served as the technical editor for Mastering Maya Complete 2 as well as consulted and beta-tested dozens of software packages. Smith has also taught visual effects and computer animation using Maya at New York University.
