Episode 096

Episode 096 – Axonometric Grids

by Richard Querin

In this episode, I demonstrate how to use Inkscape’s Axonometric Grid feature to create some simple isometric illustrations.

Note: Tom pointed out in the comments that I didn’t really explain how to get a rectangle (or text etc) onto that isometric plane. I used a simple technique for the text in the intro to this episode which I didn’t explain in the video. It’s quite useful when you’re creating diagrams. So I’ve decided to point to a PDF file I’ve created explaining this technique. It’s actually very easy. Thanks Tom. Here’s the tutorial pdf file.

While most of you won’t notice much difference in the video (hopefully), apart from some final transcoding to ogv and flv formats, I put this one together using Blender. So you might notice a short fade out to black at the end and a short cross fade between the sped-up intro and the main screencast. I’m really a big fan of editing video in Blender and it was nice to see that I could do the video editing with it. As my skills improve hopefully the end results will get better.

Also arguably noteworthy is the fact that I used my Snowflake mic to record the audio on this one. It’s still far from perfect (it sounds a little overmodulated to me at times), but I think it’s better than the noisy hum-ridden Logitech headset that I’ve been using. I’m definitely going to tweak the positioning of it.

If anybody’s interested in attending the Ohio Linux Fest on September 25,26 in Columbus, both Heathenx and I will be there. Drop us a note in the comments if you’ll be attending and maybe we can meet up.

**** Note: I think there is something wrong with the streaming OGV file. The flash version plays fine (in non Firefox3.5 browsers) but when viewing the streaming ogv file in FF3.5 it seems to stop right after the inital 12 sec intro. At least on my machine. I’d really like others to fill me in on whether or not the streaming ogv file played correctly in their FF3.5 browsers for them.

**** Update: I’ve temporarily made the streaming version Flash for everybody so it should stream fine now. We’ll switch it back once we get it fixed.

**** Update 2: Heathenx has saved the day and corrected the problem. It’s now ogv and working fine.

44 Responses to “Episode 096”

  1. Richard Querin (rfquerin) 's status on Friday, 11-Sep-09 02:59:20 UTC - Identi.ca Says:

    […] New screencast is up: http://screencasters.heathenx.org/episode-096/. […]

  2. Richard Querin (rfquerin) 's status on Friday, 11-Sep-09 03:02:30 UTC - Identi.ca Says:

    […] http://screencasters.heathenx.org/episode-096/ a few seconds ago from web in context […]

  3. nico Says:

    Firefox 3.5.3 on Fedora 10, streaming video stops at 00:10 πŸ™
    Great job you’re doing on this site, anyway, it’s always very useful, thanks!

  4. Bugs Bane Says:

    Same on FF 3.5.4 on Kubuntu Jaunty 9.04 πŸ™ The first 10 seconds look/sound great, though!

  5. jarleih Says:

    Same on FF 3.5.3 on Windows XP. Video stops after 10 seconds.

  6. franckbenoit Says:

    Same for me : jaunty, FF3.5

  7. rfquerin Says:

    Thanks for all the feedback. I’m assuming the ogv plays fine for anybody who’s downloaded it and watched it offline right?

    Oh.. and I blame heathenx. πŸ˜‰

  8. TeresaW Says:

    Nope. sorry, 14 mins of nothing after the intro. I hope you have backed up your work.

  9. rfquerin Says:

    I’ve just made the flash fallback the default for now.. until we get it fixed. Sorry bout that folks. The streaming version should play fine for everybody. When I get the ogv issue sorted out I’ll switch it back. Again, thanks for all the troubleshooting info.

  10. pixhektar Says:

    Downloaded OGV is fine for me. It is very useful screencast, thank you for making it.

  11. Don W Says:

    Ditto above on Vista and FF3.5.3. Also can’t DL by clicking on either download option button. Right click and ‘save link as’ works just fine.

    Good tips on the grid use.

  12. heathenx Says:

    Okay everyone…the video has been fixed and should stream normally again. I’ll have to take the blame for this one since I didn’t check if the video actually played in FF3.5 before uploading it. Seems to play just fine now. Sorry for the hiccup.

  13. Lagr Says:

    Hey the two of you do great work!! thanks much for both the technical advice, and constant upgrading of your personal skills with the tools of the bleeding edges. Sidenote, yes of late any of the streamed OGG flies have been freezing @ no real specific intervals, but I’m hopeful that the update to FF3.5.3 takes care of that as well as recently seeing that the flash player was a bit dated too Regardless, the efforts here are very usful, and entertainingly educative..keep up the awesome efforts

  14. heathenx Says:

    @Lagr
    Thanks for understanding. I really think it wold be a fabulous feature if the HTML5 video tag in FF3.5 could be flipped on and off per the user’s preference. It would be great for folks like us who offer a flash fallback. That way the user could decide to avoid Theora if they felt it wasn’t up to snuff on their hardware. Perhaps there is a way to do it now.

    I think Richard and I are still waiting for a Theora Messiah to come along to teach us how to to properly encode with the Theora codec with uber streamability. Regardless, I still keep a candle lit for Theora. It has to improve.

    @rfquerin
    Btw, nice screencast. Very practical. πŸ™‚

  15. TeresaW Says:

    Yay! It works! 14 mins of something. Thank you very much, this is just what I needed at this moment in time, for my 3D virtual remodelling of my flat project, from floor plans. (How to persuade my hubby to put hand in pocket for improvements and learn something technological for myself at the same time).

    Thanks for the lesson, it has saved me hours. πŸ™‚

  16. lx Says:

    Thank you so much for your great jobs. I’ve download all your videos and I’d like to share with all “inkscapers” in china freely.I wonder if it’s leagal.

  17. rfquerin Says:

    Ix,

    Yes it is.. with a couple of things to note:

    Our screencasts are released under a Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0/). The license we chose means you can share the videos as long as you do a few things:

    – give us attribution.. meaning you let people know where you got them
    – you can’t sell them.. but all non-commercial uses are perfectly fine
    – when you share them, you have to do so under the same license terms

    Hopefully that’s clear enough. We love when people find our stuff useful enough to share with others! Thanks!

  18. JimR Says:

    Great stuff Richard, thanks a lot! Downloaded video plays fine (in VLC).

    This is just the kind of illustrations that I would like to do at work (sketching new product concepts) and this method supplements the traditional hand drawings we use (coloured in Paint Shop Pro X2). Inkscape is also very good for making small icons.

    Voice sounds fine, new mike is good. If you want to improve sound even more you would have to look at acoustical treatment of the room you are sitting in πŸ˜‰ I can hear hard walls and some room resonanses (yes I’m a home studio recording geek!).

    JimR

  19. rfquerin Says:

    @JimR,

    Oh yes.. the room could definitely use some acoustical treatment. I’m also sure that the mic positioning could use lots of work. The Snowflake mic comes mounted to a bracket which just sits atop my laptop screen about 16″ directly in front of me. I’ve got a medium sized Gorillapod articulated tripod thingy as well as a little mini Manfrotto tripod. I’m wondering whether I could pull a McGyver and mount the mic on those and get it closer but to the side a bit.

    Maybe I’ll throw a blanket over myself next time to dampen out the reverb. πŸ˜‰

    Thanks for the comments and glad that the subject of the screencast might prove useful.

  20. narayan Says:

    Great tutorial- as always! πŸ™‚

    There is a low-frequency hum riding on the audio.
    Probably filtering out the audio below 100 Hz would solve the issue.

    Since you use Linux, probably it would be easier to do this.
    (AFAIK, Windows does not have an equalizer for the MIC IN incoming signal.)

  21. Darth_Gimp Says:

    As much as I know and use Blender, I haven’t spent much time in the sequencer. Would you be willing to share how you are using Blender with the screencast?

  22. narayan Says:

    I Googled for “blender video edit” and found that Richard has posted three screencasts on this very subject, and they are all listed right here at this website!

    But strangely, there is no direct linkage at this website:
    1. There is no index of those screencasts.
    2. You cannot find a way to them from the home page,
    3. A search on the same keyword at this website does not list them.
    4. The video repository does not list them.

  23. rfquerin Says:

    Yes. I’ve done 3 of them so far. The reason they are not part of our Inkscape screencast site is exactly that.. they are not Inkscape screencasts. πŸ˜‰

    But that won’t preclude us from perhaps making a site focusing on Blender video editing.

    That is not to say we aren’t doing anything about that either. πŸ˜‰

    Stay tuned for now.

  24. narayan Says:

    Well, it’s only the tag line that talks about InkScape.

    The site name itself is not linked with InkScape: It says “screencast”; nothing more.

    Why not place all the tutorials under one single roof? πŸ™‚
    Just change the tag line to “InkScape and Blender” and carry on with the excellent work!

  25. rfquerin Says:

    I think we’re planning something a little different. Not that it won’t end up being under the same banner, but it won’t be quite the same approach. We’re still trying to figure out exactly what the goal is and how to best achieve it.

  26. heathenx Says:

    @Darth_Gimp
    I suppose I could link directly to the three screencasts that Richard has made but perhaps I should link back to his blog where they originated. Here you go:

    http://blog.rfquerin.org/2009/01/26/how-i-edit-videos-using-blender-maybe-part-one/

    http://blog.rfquerin.org/2009/02/14/really-basic-blender-video-editing-part-2/

    http://blog.rfquerin.org/2009/07/23/blender-video-editing-screencast-no-3/

  27. Mark Says:

    slightly off topic. I tried doing a couple of your earlier tutorials, the clock and the red sky inc ones. i couldn’t get the clone tiles to line up the way you did it (i managed to get the desired result after an extra tweak or two) . My question is do some of these tools produce different results in windows?

  28. Tom Says:

    Another great tutorial. Thanks!

    Is there a simple way to add curves to the shape outlines? You sort of hinted at it but didn’t ellaborate. I’d like to achieve something similar to the orange areas on this diagram…

    http://commons.wikimedia.org/wiki/File:DMZ_network_diagram_2_firewall.svg

  29. rfquerin Says:

    @Mark – It’s possible but I haven’t found much difference between the windows and linux clients. Maybe Heathenx will have something to add here.

    @Tom – Actually, that’s something I should have covered. Here’s a link to a tutorial diagram I just did showing how to get rectangles down onto that isometric plane. It’s pretty straightforward. I think I’ll add the link to the pdf file directly to the ep096 post since those steps are valuable to know and I didn’t explain them. Thanks for pointing that out. Btw, it’s the same technique I used for the text in the intro to this episode. Here’s the file: http://screencasters.heathenx.org/_misc/isometricplate.pdf

    Hope it helps, but I blame heathenx if it doesn’t. πŸ˜‰

  30. Tom Says:

    @rfquerin – Splendid! πŸ™‚

    It’s quite tricky. I’ve just realized that it’s also possible with the Bezier tool itself by cutting the corner instead of creating squared corners – obvious really. The tutorial was great timing for me as I decided to draw some network diagrams using this style after I saw the image in my previous link.

  31. heathenx Says:

    @Mark
    I agree with Richard. There isn’t much difference between the Linux and Windows versions as far as feature functionality (that I have ever noticed anyway). However, we’re always careful to mention which release of Inkscape that we used to make the tutorial. The tutorials that you mentioned were made in 0.45. Without digging into your issue I suspect that maybe some minor things have changed between .45, .46, and .47 regarding tiled clones. If it takes an extra tweak or two on a newer version then so be it.

    To be honest, I haven’t needed to use tiled clones in a long time. I appreciate that we have this feature but I hope at some point the entire titled clone dialog gets a clean up so it’s easier to use. I find myself fiddling with settings way too much before I get what I wanted. Using percentages rather than pixels drives me up a wall but we’ll keep that on the down low. πŸ˜‰

    @Tom
    Here’s a method that I use to draw isometric circles. I learned it from Vectortuts. Perhaps you’ll find it handy.

    http://bit.ly/2rfohB

  32. narayan Says:

    Any particular reason why you reduced the height to 86%? Does it follow a formula like “multiply by square/cube root 2”?

    The height would appear MORE than the width when we see a circle at an angle but which is level with the eye. Here the effect is as if we are looking DOWN at it.

    What is the formula behind this?
    ***

    BTW a tip for newbie readers: Press CTRL down while doing the last two steps.

  33. heathenx Says:

    @narayan
    I’m not sure where the 86.062% comes from. I learned it that way and never thought to question it. It works perfectly. All I know is that it’s what it takes to get the 4 segments on a square equal according to an axonometric grid. I must say, though, I’m a little curious about it now.

    I can barely remember another way of learning how to draw circles on an isometric plane from my school days when I was drafting on the board. Something about drawing equal radii on top and bottom and then smaller radii on the sides by finding the midpoints. I’m sure the same could be done in Inkscape if we had better trimming functions like that found in CAD applications. Trimming to tangents is a bit cumbersome. Cody Walker’s method (Vectortuts) is much faster though. πŸ˜‰

  34. narayan Says:

    Well, this page explains the theory and also the conversion factors.
    http://www.compuphase.com/axometr.htm

    InkScape’s grid must be following one of these schemes, though.

    the cube is first turned on its base. Then it is tilted towards the observer. Thus we see the PROJECTED lengths only (not the real ones). In fact, while the Z axis gets only turned once through 30 degrees vertically, the other axes get turned twice. This changes their apparent lengths.

    So the ratio you found must be the final ratio of the APPARENT lengths.

  35. JimR Says:

    I was drawing the hollow box and I tried adding a circular cut in the side wall. I had some issues getting the circle correctly skewed, I will try the skew+rotate method on circles next.

    I could use some of the earlier described methods of copying+offsetting the circle, then using ‘difference’ to get the ‘slice’ that imitates the thickness of the box inside the circle cutout. When the slice is given a gradient it starts looking pretty decent πŸ™‚

    It’s interesting how Inkscape is slowly taking over more and more of the conceptual product drawings at work. We take a hand drawing, insert it on a layer, then draw the products on top of it. Being able to work in the correct size and move parts around to show different product use stages is very valuable and saves a lot of drawing time. We have evolved from black&white pencil drawings into 3D drawings with colours added (Paint Shop Pro X2) and now vectorized drawings in Inkscape.

    Inkscape dows not replace PSP but it supplements it very nicely and we are using ‘trace bitmap’ a lot too, what a great feature! Hand drawings get a lot cleaner and ‘cooler’ after tracing and the fact that you can trace a small picture and get it up to any size in any colour is really great. We are now two guys doing Inkscape and I’m working on the rest of them πŸ™‚

    Regards

    JimR

  36. Zlatko Nikolic Says:

    Friends its to much OFF TOPIC dialog here. I like this tutorial, it can be apply one many other things like drawing a blueprints of some tech stuff, pc speakers, pc case… in many catalogs is use this kind of perspective drawing, 3D like look but not real life perspective. I have one question is any way in Inkscape to made circular grid, Gimp have that kind of grid.
    Thanks – regards.

  37. heathenx Says:

    @Zlatko
    Yes, there is a new polar grid feature in 0.47pre2. Give it a try. πŸ˜‰

  38. Zlatko Nikolic Says:

    @Heathenkx
    I just install 0.47 pre2 and find polar grid in render option, but this is not real grid, I will like real polar grid with snap to that kind of grid. On this render kind of grid it can be use like guide line, but not with 100% technical precision.

  39. heathenx Says:

    @Zlatko
    It’s the best we have at the moment. Unfortunately, you’ll have to make do or not use it at all until something better comes along.

  40. Zlatko Nikolic Says:

    @Heathenkx
    Thanks for polar grid tip, it can be very useful by make more nodes on grid and than use snap to nodes, and I like options in menu of polar grid, there are very good organized.
    I will like to see some tutorial with mixed import an export of SVG files into Scribus and back, if its possible, I realy hope that Im not bug in your Screencaster team.
    Regards

  41. Tellier Says:

    Bravo, a chaque visite j’apprend quelque chos de nouveau. C’est gΓ©nial! Beau travail.

    Merci!!

    jft

  42. Aurelian Design Says:

    I think the cat is just trying to tell you to teach us to draw a cat bowl.

    Seriously, great tutorial, as always.

  43. Xbody Says:

    One of the greatest tutorials ever. I like this very much. Short and good. πŸ™‚

  44. La griglia assonometrica in Inkscape | aldolat Says:

    […] La griglia assonometrica in Inkscape […]