With the addition of mesh objects we have some nice possibilities for creating new things in Second Life. Ashasekayi made a great 6 part clothing/rigged mesh tutorial. Gaia also makes wonderful tutorials for working with sculpties, going from sculpties to mesh, and mesh. They have the basics pretty well covered. I want to get beyond the basics and find more Blender features. I have found several features that can help with modeling and in particular with making clothes. This article is about one of the Blender features.
Looking through loads of tutorials I’ve found some I think are pretty good examples of how to use the feature for making clothes look like they are made from real cloth. This is not a complete how to make a top. This is about a feature you can use in making a blouse.
Cloth Simulation – This is a feature in Blender that I have seldom seen discussed in Second Life circles. I wanted to explore what it can do and try it out. I used Blender 2.59.
Sorting Through Tutorials
YouTube has a gazillion tutorial videos on Blender and Second Life. The problem is finding the ones that have good information and are laser sharp to the point. Ashasekayi and Gaia polish their videos. So, I tend to be spoiled. Many leave all their mistakes and missteps in the video, which wastes my time and makes them hard to understand.
To find the tutorials that let me make cloth-like clothes I had to learn some new terms. In Maya, 3DMax, and Blender the animation and physics engines have features to animate cloth. Something we cannot do in SL. The term for it is Cloth Simulator or Soft Body, some write softbody as one word. The feature is used for more than just cloth. If you search for soft body test on YouTube you will see animations using soft body for a number of things.
Searching for Blender 2.5 Cloth Simulator gives you a set of videos. Searching for Blender 2.5 cloth or clothes soft body gives a similar but mostly different set of videos.
For our SL clothes we probably won’t be animating cloth for some time. However, the recent addition of enhanced avatar physics may be a clue that Linden Lab (LL) is headed that direction. Whatever the case, for now it is too complicated. We will have to be satisfied with mesh moving with the avatar. But, we can still use Blender to make realistic looking cloth.
In Blender the cloth simulation/soft body animation is deforming a selected mesh according to mathematical equations that approximate real life effects. It is an engine in Blender that is doing the work to rearrange all those vertices. In Blender we can see cloth move and breasts jiggle. The neat thing is we can stop the Blender animation at any point and take a copy of the deformed mesh to use for our clothing item.
So, I needed to find a good cloth simulation or soft body tutorial that would help me accomplish my goal. The image above shows the type of cloth folds I would like to add. Whether I have the patience to get there is another matter.
Since most tutorials are made by geeky guys, no offence intended, I doubted I would find any providing fashion design tutorials. One I found that is really down to the basic idea is by 20jreid10.[youtube NmOQj4tsqfk]
This video gives you the ideas and basic settings in Blender 2.5. \o/ I looked through lots of videos to find this little puppy. It gives a good coverage of cloth and animation tasks I need to accomplish.
If you want to learn more about the possible settings for cloth simulation, watch: Introduction to Cloth Simulation on Blender Cookie. It explains most of the settings available in the Cloth Simulator.
My Experience Making a Poncho
I want to make SL mesh clothes so the object I am going to have the cloth collide with (think drape around) is the avatar. I’m using the avatar model I made using Ashasekayi’s and Gaia’s tutorials. I have an avatar mesh that is a head, upper, and lower body with all the vertex groups setup. See my article Second Life Mesh Clothing Tutorial for a narrative of those tutorials. Also, for now I’ll ignore the vertex group thing, because it deals with stuff I’m still learning.
I’m going to start out with a poncho for a learning project. My first step is to open the avatar file and save it as another file, in my case poncho. You can see in the image showing the 3 piece avatar that I’ve put material on my avatar so I can tell the composite from the 3 piece version. I made my first try with the 3 piece model (head, upper, and lower).
Next I need a mesh for the poncho. I made a mesh plane scaling and rotating it to give me the size and shape I want. Pressing N to open the numeric panel I scroll down to ITEM and rename my plane to Poncho. That will make it easier to keep track of what is what as I work in the Outliner. Ashasekayi’s tutorial makes good use of the Outliner and explains it.
One needs to subdivide the poncho to get it to deform in a way that looks like cloth. For my first try I went a bit insane. This is far too many polygons for a clothing item. But, I wanted to see how long it would take my computer to render the cloth. My Duel Core2 2.4ghz finished in about a minute.
I need a hole for my head and neck. I use a Boolean feature to cut the hole. I exit Edit mode then make a cylinder without end caps. By exiting Edit mode I get separate objects, which I’ll need for the Boolean function. You can see I deformed the cylinder to make a V-neck opening. Then I poke the cylinder through the poncho mesh.
Next I select the poncho and apply a Modifier to it. Click the Wrench in the Properties Panel. Add a Boolean modifier. I used a Difference modifier to subtract the cylinder from the poncho. To the right of the ‘Difference’ sector is an empty object field. Type in: cylinder (when you click in the field you should get a drop down with the names of objects in the scene). I am assuming you do NOT have any other cylinders in the scene. Naming things in complex models avoid confusion. Apply the modifier and you can delete the cylinder. Now you should have a nice neck opening.
UVMap – I want to add a texture to the poncho at some point. While the poncho is a nice flat plan would be a good time to unwrap the UVMap. I’m going to skip showing how. But, at this point it is easy. There are lots of video tutorials on the subject and Gaia has one labeled: Sculpted Prims II. UVMaps work the same for Sculpties and mesh.
Next select the poncho. There are different ways to do the same thing in Blender 2.5, I think selecting the Physics button in Properties is best. The icon is at the right end of the properties buttons and looks like a bouncing ball with a swoosh. You can make cloth by adding a cloth modifier, but you end up going to Physics as the second step, so I just start with Physics.
Once you select the Physics Property you’ll see options for Cloth, Collision, Soft Body, and etc. Click Cloth. You’ll notice once a button is selected itgets an X. If you click again it will remove the cloth modifier from the poncho. Next Select the Upper Body of your avatar. Properties is still open and you can see it changes when you change the selection. Now click Collision in Properties. My poncho is short but I also made the lower body a collision object too, which isn’t necessary. But, I’m playing.
NOTE: As you move through making your cloth simulation, you should probably have your animation timeline open. If you are not on Frame zero of the animation the poncho can disappear. It isn’t gone. It is just invisible. So, if you lose your cloth item, check to see if you are at Frame zero.
Now you can press Alt-A to start the simulation. It is fun to watch. The first pass is slow. After that the simulation is more like real time. Blender has cached the deformations and does not have to calculate them on subsequent passes.
As long as the cache is live you can jump from frame to frame. That is handy for picking a point in the simulation that you like. Once the cache clears, on any frame but zero the poncho becomes invisible.
The next step is to get a copy of deformed mesh we can work with. Trying to duplicate the poncho does not work. You get the mesh from frame zero and at any frame but zero it is invisible. So, to get the deformed mesh click the Wrench in Properties and you’ll see the Cloth Modifier is in use. Click Apply to apply the current deformation from the simulation. Ta-Da! Now we have our deformed mesh that looks like a cloth poncho.
I suggest you save the Blender file before you apply the Cloth Modifier. Then save again using a new file name. Use the new file to finish the poncho. This will let you to come back later and make new renders of the poncho.
At this point the poncho is a static mesh. It won’t follow the avatar’s movements until we rig it to the skeleton/armature.
In Ashasekayi’s video all that was needed for the T-shirt like top to move was to make the armature/skelton the shirt’s parent and run the Bone Weight Copy tool. See Second Life Mesh Clothing Tutorial for an index to Ashasekayi’s tutorial.
One can do the same thing with the poncho and it will move. But, it is not going to come out as well as the shirt did. You can see in my video that an unmodified weight copy has some problems… lots of them. Turning up the quality only helps a tiny bit.[youtube yw7D_np-164]
These problems are typically fixed by changing the vertex groups and the weight painting. A poncho goes against the grain of avatar movement because it does not lend itself to the avatar joints. A poncho does not bend at the waist when one bows. In RL it would more or less hang from the neck. I have yet to figure out how to do that.
I don’t know enough to know if changing the vertex painting is going to make the poncho usable. Since this tutorial is about the Cloth Simulation tool I’m not going into vertex weight painting. So, I’ll to stop here.
The idea was to show you what Cloth Simulation can do. I’m not going to get the neat tops shown above just using Cloth Simulation. That will take some serious work. But, I at least have another tool for helping me get there. There are other tools to help create clothes. I’ll cover those as I get to them.