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TOTAL DURATION: 59m 10s

To manage pipeline workflows, you can turn to Task Operators (TOPs) which are built using a technology called the Procedural Dependency Graph (PDG). Workflows created using PDG use TOP nodes that generate work items that distribute tasks to either your local computer or a larger compute farm.

In this lesson, you will use TOP nodes to take a city map, create buildings for each city block and then grow this system to handle more complex buildings and larger city maps. Houdini artists will probably know how to do this in SOPs, but by using TOPs, you can learn the PDG workflow while creating a system that can be easily scaled to distribute multiple tasks to an external compute farm to process in parallel.

The complete Houdini Foundations for Houdini 19.5 is also available as Downloadable PDF and a Print-on-Demand book through the Lulu Ebook company. This 224 page book contains 9 chapters designed to help artists take their first steps into Houdini.

Research for this lesson by Michael Buckley

CREATED BY

rmagee
ROBERT MAGEE

Robert Magee is a Senior Product Marketing Manager at SideFX who has been working with Houdini for 20 years. He has created lots of learning material and demos designed to help artists understand how going procedural with Houdini can benefit their work.

More from Robert Magee

COMMENTS

  • TwinSnakes007 1 year, 9 months ago  | 

    This level of detail is much appreciated- into the black box of pdg/tops. The sops synergy is an added bonus of even procedural options into existing sops workflows.

    SideFX has been killing it with these last series of tutorials that have come out - with PDF’s too boot!

  • j00ey 1 year, 9 months ago  | 

    Thank you for this, it's very useful.

    One question - On my machine when I use the service cook-type, it runs through all the work items very quickly - except for 3, and which 3 varies. Does that ring any bells?

    • DennisSmolek 1 year, 5 months ago  | 

      Did you ever resolve this?
      When I use "Out of Process" it runs 4 at a time ina pretty slow but steady pace.
      When I use the service it blazes through what looks like 10 at a time but then gets stuck on 6 and spins seemingly forever...

  • Quelltroi 1 year, 9 months ago  | 

    Beautifully-designed pdf/book that reeks with vigor and a magnetic freshness.

  • chavinskyblahblah 1 year, 9 months ago  | 

    the ImageMagick node are not work it gave me this ERROR: Could not find the ImageMagick executable

  • kenchen19 1 year, 9 months ago  | 

    Hello, but I did not find the GeometryFile file referenced in the second tutorial in tops_lesson_start_geo.

    • Kokesh 1 year, 7 months ago  | 

      Yes, my "geo" file is empty too. Tried to download repatedly but with the same result. Any idea?

    • Kokesh 1 year, 7 months ago  | 

      Problem solved -> I saved the project in a different file than the original lesson. So I found the new "geo" file in the new one I made.

  • vinyvince 1 year, 9 months ago  | 

    Thanks, it's cool but i feel it's very similar tutorial has already been published. I would like more advanced than redundant basic content, like the machien learning tutorial posted few year agos which some parts were also skipped

  • cliffordart3d 1 year, 4 months ago  | 

    Would love to follow this one along but it looks like the geo folder provided is empty

    • rmagee 1 year, 4 months ago  | 

      All the geometry is generated during the lesson - there are four images of street grids that you will use to generate the city blocks and then the buildings themselves.

  • buse.duz 1 year, 4 months ago  | 

    the ImageMagick node are not work it gave me this ERROR: Could not find the ImageMagick executable, i am getting the same error any reaason it could be that?

  • derekthegood1 1 year, 3 months ago  | 

    I really appreciate all the exercise. Everything works except for the imagemagick node. I too, get an error:
    [22:44:58.723] Running with PID 42472
    [22:44:58.724] ERROR: Could not find the ImageMagick executable

    Using what I learned thus mar, I LMB clicked and confirmed that all input files were being generated, but the output file is missing.
    $HIP/images/city_01.imagemagick1.0.png

    The expected output says it should be
    I:/Houdini/tops_lesson_start/images/city_01.imagemagick1.0.png

    My guess is that since all 4 files are being generated with the correct text overlay, there must be some issue with the node execution

  • hitariq 1 year, 2 months ago  | 

    Thank you so much for the lesson, however I am a stuck at the second video where you use the file node to enter '@pdg_output'. That is not working for me.

    • mattiacon92 1 year, 2 months ago  | 

      Hi, did you manage to sort this out? I am having the same issue. Trying to understand whether that's happening because I am using the Apprentice version.

    • HArrCorr 1 year, 1 month ago  | 

      i think you have the wrong symbol. try grave accent `@pdg_output`

      • heidi-ya 11 months, 1 week ago  | 

        I'have same question!!Can l ask you how fix this question?although I write `@pdg_output` that doesn't work

        • newkinostudio 11 months ago  | 

          yeah I'm not sure if it's a backslash as he says in the tutorial.

          • newkinostudio 11 months ago  | 

            just tested `@pdg_output` and it worked!

    • a_p_92 7 months ago  | 

      My Geo File isnt inside the Folder!
      pls Solve my Prob would be nice that i can take next steps

  • Ela_Eichu 9 months, 1 week ago  | 

    Hi unfortunately the incoming file node in the build_streets network doesn't work for me (Part 8). I get :

    Error
    Please specify a geometry file.
    Warning
    Local variable 'pdg_input' not found.

    I tried both 'pdg_input' as on the videos and 'pdg_output' as on the PDF and none gives me results. The city disappears.

  • mtea9152 8 months ago  | 

    Be careful as the symbols ' and ` are different.
    I often make mistakes and get warned.

    • mtea9152 7 months, 4 weeks ago  | 

      I had trouble installing "Image Magick".
      I have little experience with command line operations.
      I don't know the "$PATH" setting.
      The path was directly specified in "ImageMagick Node".

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