Qt3D

Basically, this page is about the debian package that I built from the ​GitHub sources, compatible with Qt 4.8.1. If you want to just download the package, skip the whole stuff and jump here.

However, let me first dwell here a bit on the ​Qt3D module of the ​Qt environment.

I have been using it for quite some while (Qt version 4.8.1), whence it was available as a gitorious repository and basically in full functionality. The example that started it all was the "teapot". Qt3D not only draws 3D objects through triangles ("tesselation") but also a nifty magic: It has a second buffer where for each pixel in the real image it will draw a another pixel in the second buffer in a certain fixed color. This color is defined by assigning a 3D object an object id. When the user is clicking the object, the color is picked from the second buffer and the program knows which object the user has tried to access.

This is the very functionality that I require for molecuilder. Atoms are 3D objects (spheres) and I want to make them clickable for selection, ...

This is all nice and shiny cause Qt3D seemed very stable and well-working. However, it never (for like 4 years up till now) integrated into the full Qt environment. I don't know why but even with Qt5.5. it is still a "tech preview". However, to me, this was the sign, that Qt3D is becoming final and it is worthwhile to invest some time into making molecuilder into a debian package including the GUI.

Making a debian package

First of all, I refer to branch "qt4" that was once available on gitorious.org. The commit hash of the HEAD is fdad0d7f39dfbc883372628fcc58c1194ab0b782.

Then, I had to make the following changes (see patch file in attachments):

• I removed libqt4-declarative from the ..Depends in debian/control
• I added lots of folders and files to install-desktops target in debian/rules

With these changes (already contained in the archive file found in the attachments) you can build the packages as follows,

debuild -us -uc

Note that adding something like "-j4" will speed up compilations. But it doesn't take too long anyway (compared to MoleCuilder).

Note that the dependencies should be fulfilled beforehand. I compiled the packages in the attachments on a virtual machine with a freshly installed Ubuntu 12.04.5 with minimum requirements.

Note finally that I am not in any way affiliated with digia (the company owning Qt) and all my modifications are covered by the LGPL license (go that from wikipedia.org). The only reason I make Qt3D available as debian package is for you to be able to use molecuilder with the GUI.

What you need

Downloading the package: See the attachments below, just pick libqt4-3d_1.0-tp2_amd64.deb and install as

sudo dpkg -i libqt4-3d_1.0-tp2_amd64.deb

These packages have been built for Ubuntu 12.04. How they behave under different distros is undefined.

The other packages then do the following:

• libqt4-3d-dbg_1.0-tp2_amd64.deb contains debugging symbols for the Qt3D library. In case molecuildergui crashes and you want to take a look yourself, download and install.
• libqt4-3d-dev_1.0-tp2_amd64.deb contains the header files required if you want to build the molecuilder debian package yourself.
• libqt4-3d-examples_1.0-tp2_amd64.deb contains the examples from the Qt3D package, e.g. teapot

Note that the upstream tarball has been split into two parts due to size constraints (of the TRAC). Please join them by

cat <libqt4-3d_1.0.orig.tar.gz.00 >libqt4-3d_1.0.orig.tar.gz
cat <libqt4-3d_1.0.orig.tar.gz.01 >>libqt4-3d_1.0.orig.tar.gz

and additionally check the sha256sum: f56379703b48d670abfa733ee32278db772d2c1e1890704ba4eef91586a5b009