Installing an older version of OS X


May be you find yourself in a situation where you need to install an older version of OS X, to test a software or to provide support for older versions since not everyone need to move at the speed

that OS releases cycles dictates. In Apple case that’s a problem as they don’t make it easy. Here’s some tips that could help you to do that. Shortly after a new version is released they make it impossible to just run the older installer within a more recent version.

With OS X El Capitan, Yosemite, or Mavericks, you can use a USB flash drive or other removable media as a startup disk from which to install OS X.

1-Using the Disk Utility create the partition where you will install the older version


2-Make sure you have an installer of the old version you need, either from a backup, a disk, an image, etc

3-Mount your USB flash drive or other volume. You could also use a secondary internal partition.

4-Open the Terminal app, which is in the Utilities folder of your Applications folder.

5-Use the createinstallmedia command in Terminal to create the bootable installer.  For detailed usage instructions, make sure that the appropriate Install OS X app is in your Applications folder, then enter one of the following paths in Terminal:

The following examples assume that the OS X installer is in your Applications folder and the name of your USB flash drive or other volume is MyUSB:

Example for El Capitan:

sudo /Applications/Install\ OS\ X\ El\
createinstallmedia --volume /Volumes/MyUSB--applicationpath 
/Applications/Install\ OS\ X\ El\

Example for Yosemite:

sudo /Applications/Install\ OS\ X\
createinstallmedia --volume /Volumes/MyUSB--applicationpath 
/Applications/Install\ OS\ X\

Example for Mavericks:

sudo /Applications/Install\ OS\ X\
createinstallmedia --volume /Volumes/MyUSB--applicationpath 
/Applications/Install\ OS\ X\

Then restart, press the alt key during boot to select the USB source and start the installation. If you encounter this error along the process This copy of the Install OS X Yosemite application can’t be verified. It may have been corrupted or tampered with during downloading or similar usually is because the system is detecting a more recent date than the valid range for “installing” those versions, in that case you need to follow a few more steps to trick the system date into a valid one:

While at the “Install OS X” boot menu. Pull down the “Utilities” menu option and choose “Terminal” . The manual date format to use is a little weird, it looks something like mmddHHMMccyy.

In simpler terms, that is: Month Date Hour Minute Year, and it’s entered as a solid line with no breaks or spaces between the numbers. Previously go online and research the release date and the valid range of the OS you want to install and then type any date in that range. Disconnect from the internet to perform this step and type on the terminal such a date, for example for Yosemite I’ve used date 120082315 , and then you will be able to proceed with the installation, reconnect to internet and get the correct date back.


Installing an older version of OS X

Stroking improvements

To accurately shape a stroke in QuadPaint, the user can create new pinned vertices with double click, in the future more powerful curve controls will be implemented.  Today I’ve improved the implementation by allowing the deformation to be independent from stroke density. (unlike previous algorithm) and I’ve solved a bug that prevented to simultaniously deform linked strokes.



Stroking improvements

QuadPaint control keys



This is the current main hot keys and actions to control the strokes of QuadPaint, and by changing the boundary you can control the inner quadrangulation.

Right click a vertex allows to smooth and move the stroke.

Hovering a vertex and pressing DEL , remove the vertices.

Double Click a vertex, will pin it so you basically created a new edge freely to move.

Double Click a segment, between 2 vertices will insert a new point, provided that the radius is smaller than the segment, otherwise will capture the closest vertex an pin it.

Ctrl + Click a vertex will split the stroke into 2 strokes.

Pressing +(plus) over a stroke will increase vertices count by 2. (some manual smoothing will be required to make vertices more even, will improve soon)

Pressing – (minus) will decrease by 2

Overlapping 2 vertices will merge them on mouse release.

Overlapping segments will be intersected on mouse up.

The numerical hint tells the number of vertices between 2 pinned points (inclusive), updated at mouse up.

Moving a vertices very far, after release will insert new divisions, moving them too close will merge them to maintain an average distance.

Sometimes the preview snap to surface incorrectly, but the final result will be much better because more smoothing and post process is used at execution time.


PS: seems I had some ghosts at my side because the room was completely silent and I got those eerie sounds Bouhahahaha

QuadPaint control keys

QuadPaint: your personal footprint.



Recently I’ve added two preview modes for QuadPaint:

Realtime: Where you can see changes continuously, is better suited for experimentation and small to medium patches.

Performance: Update is done at the end of every change, ideal for medium to large patches.

Off: No preview, use only if the patches have lots of self intersections and vertices count.

In every stroke, new vertices can be added, removed and pinned. Strokes can be cut and weld too. Strokes defines the boundary and also the internal polygon flow.

There are three quadrangulation algorithms as well:

Direct, it will find the optimal way to connect the existing boundary directly.

Paving: Will try to find an optimal tiling based on the boundary

Hybrid: A new algorithm that combines the best of both.

Hope you like it!

Video music: Guts and Bourbon, Kevin MacLeod.
QuadPaint: your personal footprint.

QuadPaint preview



Recently I have ironed out QuadPaint and improved lots of things under the hood. So far it is shaping into an awesome and fast retopology sketch tool.  Strokes also did allow to add, remove, collapse and split vertices for finer control over the output but is still not exposed to the GUI, I will add it soon. I’m considering also live previews so artists can have instant feedback over stroke changes. More importantly is the possibility to be the base of interesting new tools.

Hope you like it!

QuadPaint preview

Arbitrary contour retopology


Finally I’ve made quite a breakthrough in semiautomatic retopology. What initially started as a prototype tool is evolving into a quite powerful new way to retopologize models in 3DCoat. Giving artists the freedom to experiment in an intuitive way by just drawing patches, arbitrary patches that will be optimally filled with quads.

Artist is not limited to certain number of edges , flatness or any other constraint. Just draw. I’ve also added the possibility to save and load the strokes along with the model.

The core is done, remaining now is the usability and the workflow of the tool, adding a realtime preview among other details. I’m investigating several variants and further optimizations.

I suspect this core quadrangulator algorithm will span many interesting new tools.But wait, I’m saving the real breakthrough for later😉

PS: Could you suggest me a good (fast, high quality) screen capture program? I’ve tried CamStudio but cannot get +30fps recording  at 1080p😦  preferably one that is HW accelerated. (using an NVIDIA GT 560M )



Arbitrary contour retopology