More elegant operation should be provided

Again, users can add points or delete any of the points to form lines, and more elegantly, our software could allow user to drag any set of connected points to make strings they want. The idea is we could introduce the Fixed Point operation: when a user click a point with hitting F key, that point is now being marked fixed, then when the user drag the point P1 from A to C, only three points can be moved (see the green line). The behaviour of the lines to transform is no longer like the one being moved from A to B (see the blue line).

This week, I think I'm going to draw a draft interface using VS windows forms and Photoshop.

Came out a algorithm to make curves more like a strings - core technical feasibility research continues

I think that we can use weighted points to make a curve behave more like a string:

When we drag P1 from position A to B, other points should move respectively according to the its weight.

How Lines can be represented using XNA and .Net Framework

This diary was actually written one week ago on 14 of August, now I post it here.
One core thing in our project is to be able to graphicly represent knots. Users can load a predefined knot to see the looking of the knot and how the knot is created step by step. Users are also allowed to draw curves and make them to be some knots. I tried today checking to see if XNA is a good framework for our project. After three hours work on creating 3D world space, drawing some points and lines, making camera view rotated using mouse movement events, I think XNA is a powerful tool. We could use it for our project.

I also looked into the possibility of creating curves, using some well defined algorithm: Bezir curve or B-spine curve.

Drawing lines and 3D rotation have been tested. Now it is time to fine a good curve algorithm for our project.