[kde-edu]: [Step] Suggestions

Hans Chen hanswchen at gmail.com
Wed Feb 13 22:55:54 CET 2008


Ever since hearing about Step, I've wanted to try it. But somehow I forgot
about the physical simulator - until today, that is. While browsing the web,
I saw a screenshot of the application and decided to try it out. Using the
kdesvn-build script, it was build with a breeze.

I had high expectations for this application, but this... Wow! Step is going
to be one of my favorite applications for sure. I'm really impressed!
Needless to say, not everything worked as expected. Here are some
suggestions that, in my opinion, would make Step even better. Any comments
are welcomed.

*1. Palette
*This is where all the "tools" are, a central part of the application.

1.1 Have you ever tried to have the content of the box left aligned? The
different widths of the "buttons" (Pointer, Particle etc.) make it awkward
to click, especially when middle aligned. And, as a used, I'm simply used to
left aligned tool boxes.
1.2 Ah yes, the buttons should have the same width. (The "invisible" part,
at least; like Qt4 Designer).
1.3 If the box' height is too small, it should show a scrollbar. (I'm a
little bit unsure about this, but once again, see Designer).
1.4 Make the box resizable (nice if you have several boxes stacked on each
other, for example).
1.5 Make it respect top/bottom placement, or don't allow it to dock there.
1.6 A "simplified" mode, where only the icons are shown (think Photoshop
This would save space for someone who's used to the application.
1.7 Make it possible to assign shortcuts to the different "tools".

1.8 A new way to add objects to the scene: (I'm not sure this would be more
efficient, feel free to discuss)
If you click on a "button" it works the same way as now, except that it
doesn't change back to the "pointer". This way you can easily add multiple
If you just want one object, you can drag a "button" to the scene. Similar
to Designer, you drag the object to the scene. This causes a problem: this
way, you can't connect springs etc.. Maybe this could be solved somehow, or
you simply have to connect them after dropping the object?

*2. Simulate
*This was probably the most confusing. I ended up clicking Simulate -> Stop
-> Undo -> Simulate...

2.1 To solve this problem, I suggest to rename Stop to "Pause".
2.2 Add a new "Stop" action that resets everything to how it was before you
pressed "Simulate". A little bit like "Reset", but I think it would make
sense with "Stop". Think of an audio player. This is probably my most wanted
2.3 A small annoyance: the Simulate/Stop toolbar button changes size when
the string is changed. Irritating, but I don't know if there's a solution
(except hiding the text).

*3. To create a experiment vs playing with it
*I'm not really used to these kind of simulators, I can already say it has a
great potential (no puns intended). The simulators I'm used to is of the
kind "Here is a particle on a spring, set some properties and see how it
With that said, that's one of the areas where I think Step needs lots of
love. Explanation below.

The ability to create a new "World" in Step is truly great. But sometimes
you want to play with a simple experiment - I found some nice ones in
"Examples", for example the double pendulum. However, I didn't find a way to
"play" with it without destroying the actual setup. In this case, here are
the differences:

The setup is the objects, how they're connected and are supposed to
When I want to "play" I just want to change some properties: masses, the
length of the pendulum, the angle between them etc. I don't want to remove a
particle, not disconnect it. It would be great with some kind of "locked"
mode where I can play with this experiment without destroying the setup.

It's easy to say, but I realize that it's much harder in practice. What
should be consider as "locked" and what should be freely adjustable? I don't
know. But I wanted to express this wish, maybe you can find a solution?

With this, Step would just be perfect. You could introduce a "Step
Player/Viewer", which opens the .step files in locked mode without the
advanced options.
*4. Small things
4.1 I found a little bit hard to connect things (like springs) after they've
been placed on the scene, but maybe that's just me.
4.2 The application crashed sometimes, for example when clicking on
"Particle" and then "Pointer". (In the future, I'm going to post bug reports
about such crashes).
4.3 Maybe the ability to display a grid in the scene?
4.4. In the "Configure graph" dialog, I didn't really understand what the
third combobox after X: and Y: means (you can choose between 0 and 1).
4.5. Same dialog: I miss momentum as a choice as X/Y.
4.6 It would be neat if you could set a "trail" after a particle.
4.7 I would like to see a "History" box (among Palette, World, Properties
and Context info). It would simply display your latest actions and lets you
undo things. This is not very important though.
4.8 Better organized "World" box. Maybe clearer sorted by "type". Or give
the user the possibility to create "groups".
4.9 Same box. Do you think small icons in that box would look good?

*- - -*

I think that's enough for this time. As said, I'm really impressed by your
I wish I could contribute to this great project, but unfortunately neither
my C++/Qt skills nor physics knowledge is good enough. However, I'm studying
physics at the university, and when I have some free time I'll try to learn
C++/Qt. Just wait, maybe for Step 3.0... ;)

Thank you, and keep up with the superb work.

With best regards,
Hans Chen
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