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Spline Spirals

DBuchterDBuchter Posts: 70
edited December 1969 in Carrara Discussion

You may notice that I have been posting a lot of questions lately - I've been using C8.5 a lot lately for some work projects.

Anyway, this question refers to the Spiral function when creating Spline models.

My concept is to create an 8-loop matchbox-style car track. A very simple idea. Looking at the interface for creating spirals seems very straight forward. But, the output is giving unexpected results:

As you can see from the screenshot, the spiral is being created correctly except for one (un-editable) factor, which is the actual track is also rotating, or twisting on the spline. I don't want this - I want the car track on the inside at all times. This is not an editable parameter that I can find.

Any ideas?

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Comments

  • PhilWPhilW Posts: 5,145
    edited December 1969

    I just had a play and got a similar result, and I'm afraid that I can't offhand think of a way to resolve this. I know this doesn't help, but I share your frustration at this because it should be relatively easy.

  • evilproducerevilproducer Posts: 9,050
    edited December 1969

    I figured it out. Although eight loops seemed to bork it up. Four loops seemed to work. I will upload the scene file to Dropbox to DL, as it was a bit complicated to get the angle of rotation correct.

    https://dl.dropboxusercontent.com/u/7370483/Spline-Spiral-track.car

    In a nut-shell I followed your workflow. After the spiral was created, I went to the Sections menu, and chose Create Multiple. I made four loops, so I figured Carrara would space the multiple cross sections evenly. So, there are the beginning and end cross sections already in place, so I had four loops, I figured I would want a minimum of eight cross sections, so I created six. 6+2=8.

    Wellll.... Carrara didn't space the cross sections evenly, so I want to the last cross section and created some more. Unfortunately, this required several undo' before I figured out how many more I needed, so I have forgotten the number. It was either four or six. I discovered that it is best to create all your needed cross sections before the next step!

    Once I had the cross sections were created, I used the rotate tool to rotate the cross sections so that the rails of the track kept to the inside of the loop. The mesh will distort quite a bit, so don't panic. It takes a bit of finesse, and I discovered four loops is about the limit before it starts looking like a pretzel.

    My suggestion is that if you really need eight loops, to group them together, or convert to a vertex model and copy and paste two poly meshes into the VM, then bridge or weld or whatever it's called when two polymeshes are combined into one.

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    Picture_1.png
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  • Design AcrobatDesign Acrobat Posts: 459
    edited December 2013

    This is easily done in Hexagon (a companion modeler for Carrara).

    Added thicken after making the object from the helix tool in Hexagon.

    Less than $20 in the store with out any discounts.

    hexlix.jpg
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    Post edited by Design Acrobat on
  • evilproducerevilproducer Posts: 9,050
    edited December 1969

    Cool job!

    I have Hex, but have never opened it.

  • Design AcrobatDesign Acrobat Posts: 459
    edited December 1969

    evilproducer said:
    Cool job!

    I have Hex, but have never opened it.

    It's a nice modeler with some bugs, but ranks right up there with some of the ease of work flow modelers.

    I like the
    "copy on support function" which takes the instance of a single object(any object or primitive, but careful as it eats memory) and makes multiple copies on a curve (spline). Very handy for jewelry, machine parts and 3D fun in general. This one is just a sphere on a helix.

    copyonsupport.jpg
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  • McGuiverMcGuiver Posts: 219
    edited December 1969

    Sparrowhawke has a free spring primitive that would get you started.

    Spring.png
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  • DiomedeDiomede Posts: 15,158
    edited December 2013

    This seems like a perfect task for the formula modeler. Someone should be able to use the formula function, and the following links to create such a helix with minimal modeling.

    http://mathhelpforum.com/advanced-math-topics/156049-cartesian-equation-helix.html

    http://wiki.answers.com/Q/What_is_the_mathematical_equation_for_a_3-D_spiral_helix#slide1

    http://www.ahinson.com/algorithms_general/Sections/Geometry/Parametric3DSpiral.pdf

    I admit I can't.

    Getting a better handle on the formula modeler is on my to do list, right after running a marathon and learning a foreign language. But if anyone can translate the helix equations at the links to Carrara's formula modeler, it could be parameterized (is that a word?). I mean that the formula function would include parameters that could be used to adjust the width of the helix, the distance between turns, etc.

    edit - here is the documentation for Carrara's formula modeler http://docs.daz3d.com/doku.php/artzone/pub/software/carrara/06_six/22_using_formulas

    Post edited by Diomede on
  • evilproducerevilproducer Posts: 9,050
    edited December 1969

    diomede64 said:
    This seems like a perfect task for the formula modeler. Someone should be able to use the formula function, and the following links to create such a helix with minimal modeling.

    http://mathhelpforum.com/advanced-math-topics/156049-cartesian-equation-helix.html

    http://wiki.answers.com/Q/What_is_the_mathematical_equation_for_a_3-D_spiral_helix#slide1

    http://www.ahinson.com/algorithms_general/Sections/Geometry/Parametric3DSpiral.pdf

    I admit I can't.

    Getting a better handle on the formula modeler is on my to do list, right after running a marathon and learning a foreign language. But if anyone can translate the helix equations at the links to Carrara's formula modeler, it could be parameterized (is that a word?). I mean that the formula function would include parameters that could be used to adjust the width of the helix, the distance between turns, etc.

    edit - here is the documentation for Carrara's formula modeler http://docs.daz3d.com/doku.php/artzone/pub/software/carrara/06_six/22_using_formulas

    Personally not much interest in the formulas, but as to a starting point, could you use some of the parameters in the Spline modeler's spiral preset as a starting point? Just thinking out loud.

  • DartanbeckDartanbeck Posts: 21,522
    edited December 1969

    What a cool thread this is! :coolhmm:

  • evilproducerevilproducer Posts: 9,050
    edited December 1969

    Dartanbeck said:
    What a cool thread this is! :coolhmm:

    You're just thinking of racing along a virtual Hot Wheels track, aren't ya'? :coolsmile:

  • tbwoqtbwoq Posts: 238
    edited December 2013

    Here is a modifier/modeler trick for making a single spiral track section that can also be adjusted easily.

    -In the vertex modeler, extrude a profile shape(track shape) to make a single straight track along the Y axis. Only two profile shapes on each end, no subdivisions in between.
    -In the assemble room, add a 'Bend and Twist' modifier to the vertex object and set the Bend Angle value field to 360 degrees and set the Axis: to Y. You should now have a single loop shaped track.
    -In the vertex modeler, select and move one of the profile shapes(track shape) on the X axis and watch the assemble preview. The track will separate and form a spiral/corkscrew section.

    Post edited by tbwoq on
  • DartanbeckDartanbeck Posts: 21,522
    edited December 1969

    evilproducer said:
    Dartanbeck said:
    What a cool thread this is! :coolhmm:

    You're just thinking of racing along a virtual Hot Wheels track, aren't ya'? :coolsmile:You know me too well... Not fair! :ahhh:

  • evilproducerevilproducer Posts: 9,050
    edited December 1969

    tbwoq said:
    Here is a modifier/modeler trick for making a single spiral track section that can also be adjusted easily.

    -In the vertex modeler, extrude a profile shape(track shape) to make a single straight track along the Y axis. Only two profile shapes on each end, no subdivisions in between.
    -In the assemble room, add a 'Bend and Twist' modifier to the vertex object and set the Bend Angle value field to 360 degrees and set the Axis: to Y. You should now have a single loop shaped track.
    -In the vertex modeler, select and move one of the profile shapes(track shape) on the X axis and watch the assemble preview. The track will separate and form a spiral/corkscrew section.

    I'm going to have to give that a try! I always forget about the modifiers.

  • michael-kristensen_e59faa8f72michael-kristensen_e59faa8f72 Posts: 50
    edited December 1969

    Sparrowhawkes Spiral does not work on Mac :-(

    Mic

  • PhilWPhilW Posts: 5,145
    edited December 2013

    If you are thinking of running a car along this, you're going to have some fun setting up the animation! Actually, I've just had more of a think about it and it's quite easy - parent the car to a helper at the axis and set that to rotate and move along the axis, As long as the track is modelled uniformly, the car should follow the track.

    Post edited by PhilW on
  • DiomedeDiomede Posts: 15,158
    edited December 1969

    RE: formula approach. That great French site has an example. See #5 at

    http://gianp.free.fr/carrara/carrara96.html

    Which is described as "5 - Avec une hélice" My guess is that the French for helix is helice. Does anyone know if you could use the same formula (with a slight parameter change) to set the position of a car object in the sequencer? That would solve the issue that PhilW has raised about animating something along the helix.

  • DiomedeDiomede Posts: 15,158
    edited December 1969

    and the formula does work

    helix_example.jpg
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  • PGrePGre Posts: 95
    edited December 1969

    Its a lot of trial and error, but you can definitely do this all inside the vertex modeler with the deform options. The advantage is that it gives you a lot more control over the final mesh. However, the drawback is you either need work out the math first or be willing to futz with the deformer settings over and over until you get what you want.

    P

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  • DartanbeckDartanbeck Posts: 21,522
    edited December 1969

    diomede64 said:
    RE: formula approach. That great French site has an example. See #5 at

    http://gianp.free.fr/carrara/carrara96.html

    Which is described as "5 - Avec une hélice" My guess is that the French for helix is helice. Does anyone know if you could use the same formula (with a slight parameter change) to set the position of a car object in the sequencer? That would solve the issue that PhilW has raised about animating something along the helix.

    I wonder if you could use a formula to create a motion path?
    I've still never worked with motion paths in Carrara.
  • PGrePGre Posts: 95
    edited December 1969

    Here's a quick and dirty motion path. Setup using a cube keyframed to the turns, converted to motion path and then adjusted using the handles. cube is aligned to the path but rotated manually to be upside down at the apex.

    track.gif
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  • PGrePGre Posts: 95
    edited December 2013

    Whoops! Thought the GIF didn't work so posted one on Youtube. Sorry for the double.

    http://youtu.be/Rk8rJj7l4Aw

    P

    Post edited by PGre on
  • DBuchterDBuchter Posts: 70
    edited December 1969

    evilproducer said:
    I figured it out. Although eight loops seemed to bork it up. Four loops seemed to work. I will upload the scene file to Dropbox to DL, as it was a bit complicated to get the angle of rotation correct.

    https://dl.dropboxusercontent.com/u/7370483/Spline-Spiral-track.car

    In a nut-shell I followed your workflow. After the spiral was created, I went to the Sections menu, and chose Create Multiple. I made four loops, so I figured Carrara would space the multiple cross sections evenly. So, there are the beginning and end cross sections already in place, so I had four loops, I figured I would want a minimum of eight cross sections, so I created six. 6+2=8.

    Wellll.... Carrara didn't space the cross sections evenly, so I want to the last cross section and created some more. Unfortunately, this required several undo' before I figured out how many more I needed, so I have forgotten the number. It was either four or six. I discovered that it is best to create all your needed cross sections before the next step!

    Once I had the cross sections were created, I used the rotate tool to rotate the cross sections so that the rails of the track kept to the inside of the loop. The mesh will distort quite a bit, so don't panic. It takes a bit of finesse, and I discovered four loops is about the limit before it starts looking like a pretzel.

    My suggestion is that if you really need eight loops, to group them together, or convert to a vertex model and copy and paste two poly meshes into the VM, then bridge or weld or whatever it's called when two polymeshes are combined into one.

    I really appreciate the effort in figuring this out. Thanks to you and others - I've got some great alternatives.

    I do think this is a bug and I am reporting it as such.

  • DBuchterDBuchter Posts: 70
    edited December 1969

    Design Acrobat said:
    This is easily done in Hexagon (a companion modeler for Carrara).

    Added thicken after making the object from the helix tool in Hexagon.

    Less than $20 in the store with out any discounts.

    I do have Hex, but I just do not have any extra time to try to learn it at the moment. I'm sure Hex is a much better modeler than what is built into Carrara, but this particular issue now seems more like a bug than a limitation.- Thanks for adding

  • DBuchterDBuchter Posts: 70
    edited December 1969

    tbwoq said:
    Here is a modifier/modeler trick for making a single spiral track section that can also be adjusted easily.

    -In the vertex modeler, extrude a profile shape(track shape) to make a single straight track along the Y axis. Only two profile shapes on each end, no subdivisions in between.
    -In the assemble room, add a 'Bend and Twist' modifier to the vertex object and set the Bend Angle value field to 360 degrees and set the Axis: to Y. You should now have a single loop shaped track.
    -In the vertex modeler, select and move one of the profile shapes(track shape) on the X axis and watch the assemble preview. The track will separate and form a spiral/corkscrew section.

    Hmm, that sounds interesting - I may try that one too.

  • evilproducerevilproducer Posts: 9,050
    edited December 1969

    dbuchter said:
    evilproducer said:
    I figured it out. Although eight loops seemed to bork it up. Four loops seemed to work. I will upload the scene file to Dropbox to DL, as it was a bit complicated to get the angle of rotation correct.

    https://dl.dropboxusercontent.com/u/7370483/Spline-Spiral-track.car

    In a nut-shell I followed your workflow. After the spiral was created, I went to the Sections menu, and chose Create Multiple. I made four loops, so I figured Carrara would space the multiple cross sections evenly. So, there are the beginning and end cross sections already in place, so I had four loops, I figured I would want a minimum of eight cross sections, so I created six. 6+2=8.

    Wellll.... Carrara didn't space the cross sections evenly, so I want to the last cross section and created some more. Unfortunately, this required several undo' before I figured out how many more I needed, so I have forgotten the number. It was either four or six. I discovered that it is best to create all your needed cross sections before the next step!

    Once I had the cross sections were created, I used the rotate tool to rotate the cross sections so that the rails of the track kept to the inside of the loop. The mesh will distort quite a bit, so don't panic. It takes a bit of finesse, and I discovered four loops is about the limit before it starts looking like a pretzel.

    My suggestion is that if you really need eight loops, to group them together, or convert to a vertex model and copy and paste two poly meshes into the VM, then bridge or weld or whatever it's called when two polymeshes are combined into one.

    I really appreciate the effort in figuring this out. Thanks to you and others - I've got some great alternatives.

    I do think this is a bug and I am reporting it as such.

    I don't know. It could be a bug, or it could be that the programmer that set up that preset simplified it to make it easier to use with a limited number of parameters to enter.

    I actually kind of like the added control I got when I set up the cross sections. The issue that could be a bug in my mind is Carrara knotting up the mesh if you get too many spirals.

    Bug or no, what's cool about this thread is that there are many ways to accomplish the task.

  • DUDUDUDU Posts: 1,945
    edited December 1969

    dbuchter said:
    tbwoq said:
    Here is a modifier/modeler trick for making a single spiral track section that can also be adjusted easily.

    -In the vertex modeler, extrude a profile shape(track shape) to make a single straight track along the Y axis. Only two profile shapes on each end, no subdivisions in between.
    -In the assemble room, add a 'Bend and Twist' modifier to the vertex object and set the Bend Angle value field to 360 degrees and set the Axis: to Y. You should now have a single loop shaped track.
    -In the vertex modeler, select and move one of the profile shapes(track shape) on the X axis and watch the assemble preview. The track will separate and form a spiral/corkscrew section.

    Hmm, that sounds interesting - I may try that one too.

    I used this trick in my “Stupid machine” for a exercise on Carrarators forum!

    http://www.youtube.com/watch?v=xokzoqdzx7U

  • tbwoqtbwoq Posts: 238
    edited December 1969

    I used to like the spline modeler, but avoid it now unless I need simple physics method shapes. The extrusion spiral preset never really worked well for me, especially with shapes like a track. My number one feature request for Carrara modeling would be to get rid of the spline modeler and feature splines in the vertex modeler. I usually end up converting most spline models to vertex anyway.

    The vertex modeler isn't the easiest to make spiral shapes either atm. I usually subdivide a cylinder and extract triangulated lines from it, then sweep a shape profile along it. Unfortunately, even the vertex path sweeping isn't working right. A simple circle sweep has issues. I'm almost forced to use the modifier trick/workaround method for making most uniform type spiral shapes.

  • TurnerTurner Posts: 116
    edited December 1969

    Coincidentally, I'm trying to model spirals as well for a threaded product component.

    Though I do appreciate the discussion about workarounds... It's a bug. It needs to be fixed.

    Some people have time to experiment - I have time to use things that work.

  • evilproducerevilproducer Posts: 9,050
    edited December 1969

    Turner said:
    Coincidentally, I'm trying to model spirals as well for a threaded product component.

    Though I do appreciate the discussion about workarounds... It's a bug. It needs to be fixed.

    Some people have time to experiment - I have time to use things that work.

    If it works as it was designed to work, then it is not a bug. There may well be limitations in the spline modeler that make this simple preset work the way it does. I have found that most presets are starting points, because the developer of the preset cannot possibly imagine the myriad ways that it's going to be used by every individual in every situation.

    I don't think adding cross sections is a work around. I think it's more of a customization to the preset and allows for more flexibility to the modeler. We may just have to agree to disagree on this.

  • DartanbeckDartanbeck Posts: 21,522
    edited December 1969

    I think it's Geek at Play(?)...
    I saw a rather nice tutorial for making threads, like on a bolt, for Hexagon.

    Dude, if you try something that you think should work, by definition, and it doesn't... I'd definitely report the thing. The more stuff gets picked up like that the better, in my opinion. I also agree, however, with what ep is saying about his cross sections being a great way to increase control. There's a vast multitude of things that we have to really pry on our imagination and ingenuity to get them to work out. Such is the like of 3d modeling ;)

    But in this case, it just seems to me that you should be able to set an axis to follow as the spiral is taking affect. Oh... hmmm... I bet there is. Try this:
    Before applying the Spiral command, or whatever you're doing that isn't working the way you want it to, try Ctrl + Click a different axis than the one highlighted in the grids. Well... it's the grid that you click while holding down either Ctrl (Win) or Cmd(Mac). I know that this makes a big difference for Duplicate with Symmetry.

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