Survey Paper From 1996

Before the christmas break i got down to reading a few papers and managed find what looks a really relevant survery paper called:

" Computer Graphics Techniques For Modelling Cloth" by H.Ng & R.Grimsdale

This pretty much sums up most of the work done in cloth modelling and simulation up until 1996 when it was published.

The paper shows shows three main approaches to modelling cloth in the past.

• Geometrical - where the appearance of cloth is modelled - not the behaviour. The model is based on geoemetrical equations, which can represent the features of cloth like folds and creases. The mechanical properties of cloth are not concerned with.
• Physical - where the model is based on actual physical properties and behaviours of cloth. Forces are 'applied' to a piece of cloth and a simulation is ran to produce the desired shapes(s).
• Hybrid - a combination of the two, where some features are modelled geometrically and others physically.

Looking a bit at the goemetrical approaches, they generally seem simple and flexible. Where things can be altered easily in order to get the desired shape(s). Like, it is what it is; it does not have to be accurate at all. However, i think getting results that are realistic would be difficult. Furthermore, it seems plausible that basic cloth animation could be done, but not interactive simulation of cloth that can respond to its environment. This is where the need for a physical model becomes apparent. And since the aim of my project is to create a cloth simulation that is interactive, i decided to disregard geomertical methods and focus on the physical ones in the paper.

However, i found when reading about the physically based methods, a number of unfamilar concepts repeatedly leaped out and puzzled me. Additionally, there were other more familar concepts that i still felt needed some refreshment or further reading. So i made a list of these concepts which goes...

• Differential Equations and Integration.
  
• Numerical Integration.
• Energy minimization.
• Finite Difference and Finite Element method.
• Elasticity Thoery.
• Lagrange's Theroy.
• D'Alembert's Principle.
• Navier-Stokes equations.
• Multi-grid method.
• Equation 'stiffness'.
• Sparse Linear Systems.

Admittedly, theres alot to look into there but i think to really get to grips with the subject matter, a reasonable understanding of these concepts is going to help alot when reading further material.

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So i'm covering these concepts now, over the christmas break. I'm currently refreshing myself on Differential Equations, having covered them at A Level Maths but none-the-less feeling rusty on the subject.

I'll post back very soon to sum-up and digest what i found.