Hi,
I just started looking into Houdini and looking around for learning resources I found only two manuals, MAGIC OF HOUDINI and HOUDINI ON THE SPOT, which to my understanding were not updated after their first edition, both around 2006-2007.
I am looking for a description of the software logic at a more extensive, theoretical level than the one you generally get in video tutorials and wonder if these books would still do, if there are others I haven't spot or online resources which would replace them.
Many thanks!

Houdini has it's own cgwiki http://www.tokeru.com/cgwiki/?title=Houdini [www.tokeru.com] which offers a lot fundamental knowledge for free. If you want to dive deep into core principles I can recommend it.

I don't assume that you speak japanese but these might be the latest released books for Houdini:

理論と実践で学ぶHoudini -SOP&VEX編
Houdini ビジュアルエフェクトの教科書

Hi there! Some other learning resources you could use are:

HDK. Which explains a huge amount of the inner workings of Houdini.
https://www.sidefx.com/docs/hdk/index.html [www.sidefx.com]

Houdini help 17.5 version and higher.
http://www.sidefx.com/docs/houdini/index.html [www.sidefx.com]

Also Lesterbanks has a great stock pile of Houdini and vfx tutorials.
https://lesterbanks.com/category/houdini/ [lesterbanks.com]

Moin,

filipponassetti
… which to my understanding were not updated after their first edition, both around 2006-2007.

that probably is due to the fact that the software world today is just overcrowded with “fully fledged solutions”. 14-15 years ago, when those books probably where edited, you still had the chance of getting your investment back (speaking from a publisher's point of view). Today, with probable sales numbers in the very low 3-digit-range, it's just too expensive. Ebook might work, but piracy is basically killing that for special-interest.

I am looking for a description of the software logic at a more extensive, theoretical level than the one you generally get in video tutorials

Fully with you. I just had to cancel a proposition from a tutorial-company that asked me to work for them because I don't want to produce those “copy-and-paste-to-pimp-your-reel” tutorials that they are after. I even stopped producing tutorials completely because the “understand your tool” approach doesn't seem to be welcomed any more.

and wonder if these books would still do

I do not know those books, but I would definitely guess that - if they are well written and edited, not just “artist's point of view” - they should still apply in general. Aspects of Houdini will have changed (significantly), but the fundamental systematics don't seem to have been updated either :-)

Marc