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ghita

How to model this obj with sweep nurbs

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ghita    3

 

Hey everyone,

 

I started using Cinema a few months ago...not being to confident with the modelling side of it I have been building my 3D geometry with Rhinoceros and imported it in Cinema, which turned out to be a wrong idea as I now need to animate a tank slowly emptying itself of liquid with a sweep nurbs but I can't get my head around on how to....

I tried with two different sets of splines but failed both times....

 

Any help would be greatly appreciated!

 

5a58ddedd7cf5_objtobuildwithsweepnurbs.thumb.JPG.d8c9f76ea67211f296724a2339db1469.JPGobj to build with sweep nurbs.c4d

 

5a58de095561b_firstsetofsplinesfailure.thumb.JPG.ae5e3e5af34e8fe93f1e09415b85321f.JPG5a58de0ecc02d_2ndsetofsplinesfailure.thumb.JPG.0a3a64140244dffdd70114ab1ccfc083.JPG

 

 

Thanks!!

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Vizn    55

Looks like an Oil Tank. There is a primitive for that, so no need to overcomplicate things with Rhino. 

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ghita    3
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  • 2 minutes ago, Vizn said:

    Looks like an Oil Tank. There is a primitive for that, so no need to overcomplicate things with Rhino. 

     

    I would need to build it with sweep nurbs in order to animate the start and end growth.....

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    Vizn    55
    13 minutes ago, ghita said:

     

    I would need to build it with sweep nurbs in order to animate the start and end growth.....

     

    A basic Sweep generator will do that. There are loads of tutorials on the YT, and the documentation is also a good way to start familiarizing yourself with C4D.

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    ghita    3
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  • 7 minutes ago, Vizn said:

     

    A basic Sweep generator will do that. There are loads of tutorials on the YT, and the documentation is also a good way to start familiarizing yourself with C4D.

    I know that a sweep generator will do that and I have used the sweep generator to animate growth before.

    I just can't figure out how to build this specific shape with it...

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    Isleofgough    28

    I don't know why you wouldn't just animate the oil tank, but you can approximate the shape with a sweep if you really need to do this (see attached file, push play button)

    SweepOilTank.c4d

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    ghita    3
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  • 10 minutes ago, Isleofgough said:

    I don't know why you wouldn't just animate the oil tank, but you can approximate the shape with a sweep if you really need to do this (see attached file, push play button)

    SweepOilTank.c4d

    Thank you for creating the sweep nurbs for me, I still struggle with splines plane orientation...

    The reason why I didn't want to animate the oil tank, is because it has a cap at the top which my obj doesn't have, it is simply a different shape... 

     

    Thanks again for taking time and helping me...

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    Isleofgough    28

    Figuring out the splines plane orientation can sometimes be not intuitive, but it doesn't take much time to figure out the best orientation by clicking the three possibilities. In the example I gave, the spline is just a simple line with two points. One can animate the spline itself in one of two ways. The simple way is to add a few nulls and use the tracer object to connect these nulls. The position of the nulls can be animated. The more complicated way of doing this is to animate point level control in xpresso for the points on a spline. I think there is a tutorial you can find with google that explains all the options for sweep nurbs. If you are thinking of making this editable, be very careful with the options on how the spline is interpreted or you can get way too many points and polygons.

     

    If you want something very complicated, like a tentacle that is animated, there are other programs (Houdini) that give you more options, since there are limited secondary edits one can do on a procedural model in C4D without changing the model to editable (which will lose animation options).

     

    For the model you show, I would probably do that as a lathe nurb rather than sweep nurb anyway, as you can control the smoothing a points better though.

     

    SweepTracer.c4d

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    Vizn    55
    4 minutes ago, ghita said:

    I know that a sweep generator will do that and I have used the sweep generator to animate growth before.

    I just can't figure out how to build this specific shape with it...

     

    I see now, sorry. There may be a parametric way to do it, but I don't know. The only way I can suggest is animating a boole, which probably isn't what you want if you're looking to do anything else with the liquid beyond just having it disappear.

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    Vizn    55

     

    @Isleofgough I was trying to do an oil tank with a sweep before seeing your post. Now I'm looking at your Oil Tank Sweep file in r17.055 and for the life of me can't figure out how you made the filleted ends with just a circle and a line. Your Sweep has no caps as far as I can see. I made my own circle and line matching the object settings of yours and it's just a normal cylinder with flat caps. What am I missing here?

     

    Edit: Ah ha! Found it in the Details.. lol

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    Cerbera    1,968

    I'm gonna agree with @Vizn's boole suggestion as being the quickest and easiest way of doing this, using a default parametric cube boolean-subtracted from a parametric oil tank. Simply begin the animation with the cube already slightly intersecting the oil tank to get rid of its upper bulge, then keyframe the cube moving downwards until it has wiped out all the remaining 'liquid'. Or, apply a correction deformer to the tank so that you can flatten its top points out that way, and still keep it parametric. But this is one of those rare situations where using a boole is actually justified and should work predictably, and there is no need for subdivision surfaces (which would ordinarily preclude using boolean operations) if you set the segmentation in the oil tank high enough.

     

    CBR

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    bezo    521

    If you want to create some special effect of folding/unfolding object, try César Vonc´s plugin Unfolder...

    Great tool for animation of folding/unfolding.

     

    https://code.vonc.fr/?a=59

     

    Demo is restricted to single mode, but full version has a lot of modes...

    And can be used also on primitive oil tank object

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