As I concluded in my previous post for the VR project, I finished modelling the castle door, which is why in these sessions, I moved on to work on a different asset, namely, the curtains. Since we have windows in our castle, we also need curtains framing each one, or most at least. On top of that, they would have to look old and ragged because of the state of the mansion, which we chose as abandoned. I figured from early on, when we were roughly deciding on which assets to give each person, that I would need to use nCloth for the fabrics and cloth, and they would preferably need to be torn. This is why, prior to this lesson, I did some digging and found a suitable tutorial for me to follow in order to create torn cloth.
I watched this video through fully and took notes, careful to note down all of the tips and specific values set in the options menus so as to not mess anything up when doing it myself. I used these throughout the lesson and even after memorising how the simulation is achieved, I referred back to them (I’m glad I had them since going back to the video so often would be more time-consuming and having instructions in my own words was helpful in general).
I generated and scaled up a poly plane. The first step was to change the geometry, since I wouldn’t be able to make any tears with the default. With it selected, I went to ‘Mesh’ and clicked the ‘Remesh’ tickbox. With the ‘custom’ option ticked, I changed the value to 0.5 and also changed the collapse threshold percentage to 80%. When I clicked the ‘Remesh’ button underneath, the triangular, irregular patten was immediately visible on the object.
Now, with the plane in an upright position and with the correct geometry, it was time to change the Maya function to ‘FX’ and start doing exactly that – creating the effect! I selected the plan again and applied nCloth.
I didn’t just want the curtain to fall however, I needed the animation to be specific in order to create certain folds in the fabric. For this, the plane would have to hang from somewhere, which I did by selecting the two top corner verts in vertex mode, going to ‘nConstraint’ and selecting ‘transform constraint’. Once I hit play, I could see the changes, since the cloth fell/hung from the selected points.
The next part of the process was to create the tears. Back in vertex mode, I held down the tab key and selected different lines and areas of the cloth, making tear shapes where I wanted the fabric to rip. This time, in the ‘nConstraint’ tab, I clicked ‘Tearable Surface’.
As you can see, the holes appeared right where I wanted them to. Unfortunately, at this point, Maya crashed. My work was unsaved and I had to start again, but I saw this as an opportunity. I had my test run and found that the process worked. I could then apply the steps to a more appropriate size and shape for the curtains.
I got to where I was last time and had to face new issues. For example, the tears looked less organic, which was troubling albeit easily fixed with SMP. I also had to delete all of the triangular faces that had fallen and were floating in the scene.
Once I found a part of the timeline where I liked the cloth, I went back into ‘nCloth’ and selected ‘remove nCloth’ to make it a non-dynamic polygon mesh with the topology and state of the nCloth’s input mesh. Then, I could manipulate the model into a form more similar to a curtain. This was probably my favourite part of the process!
To change the shape of any of the tears or the cloth itself, I used soft-select to move the faces on larger and smaller scales. For smaller details, I removed soft-select and just used the tab to select multiple faces and move them at the same time. After modelling a quick rod, duplicating the curtain and reversing the mesh, I had the result above.
I knew I had to create multiple versions however since there is always variety in real life. With my next plane, I wanted to experiment and attempted to change the max edge strength.
This time didn’t go so well. The nCloth was all messed up and the tears did not occur along my selected areas. Instead, I was faced with a strangely torn, triangulated mess. I had to start again.
On my third attempt, I realised that the issue lay in how I was following the steps. First of all the remesh values should really be kept exact and aren’t the area to experiment with if you want the tears to be different. Second of all, I wasn’t removing my nCloth correctly, hence the floating verts. I also realised this when I tried to delete the nCloth without doing that step and the fabric material disappeared. To ensure that the shape manipulation remained, I had to select, go to ‘Modify’ and choose ‘Freeze Transformation. This was a step I had been skipping, but only after can you then delete all by type history and remove the nCloth.
I worked hard on the final look of the next two curtain versions. In the Outliner, I selected ‘dynamicconstraintZ’ and went to the attribute editor. There, I fiddled with the ‘Glue Strength Value’ to make the tears more or less intense. I also applied smoothing instead of SMP and moved around the fabric a lot more using the various basic functions. I created folds, manipulated the holes and even increased tears by deleting faces. It was so much fun since there wasn’t really an easy way to go wrong here – the curtain is supposed to look messy. I was careful not to overdo it.
