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BLSmith

Cutting Objects In Half Without Boolean.

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Hi everyone. My goal is to do this (15 second clip): 

Programs I own:

  1. Cinema4D R19
  2. Octane 4

Main Question:

  • Is there no way to emulate this effect with vanilla Cinema4D, or Octane 4? 

Context: 

  • I am animating an internal combustion engine. The model is 1.4GB, contains 900 objects, and dozens of objects are animated. 
  • If I went ahead and purchased V-Ray Renderer for it's clipping feature, it would make my investment in Octane worthless. 
  • If I went ahead and purchased V-Ray, unlike the persistent licenses I own for Octane and Cinema4D R19, I'm forced to pay $500/yr for a V-Ray subscription.

Other Options:

  • Using a boolean always crashes Cinema4D.
  • Voronoi Fracture: But I'm unsure how to have it cut exactly where I want, around all the hierarchy of objects that are animated/not-animated.. 
  • Using the Line Cut option doesn't generate caps and crashes Cinema4D. 

I'd be willing to privately link my model if that helps anyone help me on possible solutions to this issue. Thank you all for your time. 

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I don't use VRAY so can't be sure, but i've seen previously on their website that they have a VRAY Workstation monthly rental, try contacting them and ask for further details. It might suit you better if you can just rent it for a  month to complete the job and then just cancel the subscription if that's possible. 

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The only other ways I can think of would be to put the mesh in a Mograph Fracture object, and use the Mograph Effectors (R19)/Fields(R20) with a fall-off to scale the individual parts down. 

 

The problem with that is you'd need to set the axis point to one end of the meshes, and as you've mentioned, the scene has lots of moving parts, so might be long process.

 

It wouldn't be the effect as a boolean, but if the transition is quick, and there're lots of parts, it would look quite similar. 

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    I don't use VRAY so can't be sure, but i've seen previously on their website that they have a VRAY Workstation monthly rental, try contacting them and ask for further details.

    What is difficult is that using V-Ray's clipping tool also requires you to use V-Ray as the renderer, meaning I'd have to set up all materials, colors, & lights with the Renderer as well. Ideally I'd use the clipping function with V-Ray but render with Octane, but I suspect that is not possible. 

    Quote

    Mograph Fracture object

    I'm not totally familiar with this feature. Will it allow me to select all objects and perform this action? Will it work with moving objects (spinning gears, etc).

     

    Quote

    It wouldn't be the effect as a boolean, but if the transition is quick, and there're lots of parts, it would look quite similar. 

    The transition from a whole object to an object sliced in half would be relatively short (15 frames or so), but the object would remain sliced in half for 500-3000+ frames. 

     

     

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    Ah I see, niether Octane or the Fracture object would suit you purpose then.

    It might be worth looking into some free CAD software such as FreeCAD,  I remember seeing the same slice functionality you mentioned in some CAD software a few years back, I don't remeber the name of it though. You could post your vimeo link on a few CAD forums to get some additional suggestions.

     

     

     

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  • Ah I see. Correct me if I'm wrong but what your recommending is:

    • Take the CAD file I was provided, and see if I can slice it in half via a CAD program or ask the CAD Engineer who modeled the engine to do it. 
    • Convert the sliced CAD file to a sliced .C4D file (I use PolyTrans64 from Okino currently).
    • Import the sliced .C4D file into my current (full) Cinema4D file. Layer them on top of each-other, but have one disabled/transparency 0%. 
    • Transition from the full engine to the sliced engine.

    This would require organizing all 900 objects twice, and setting materials/colors/textures for all 900 objects twice, but would allow me to keep Octane. 

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    If you're able to slice it in some CAD software and export that animation as an alembic (.abc) or .FBX, (or search for an exporter that can do this) you could then import that file into C4D, and use Octane as you normally would. 

     

    I don't have any other ideas unfortunately. 

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    I don't have any other ideas unfortunately. 

    This idea you have could work! At the risk of going down the rabbit hole...

     

    Is it possible to take the .C4D I currently have, save it as an .abc or .FBX, import it into CAD software, cut that in half, then re-import it into C4D? This way my object structure doesn't completely get lost. The 899 objects were all manually relabeled, organized, and structured to be animated within Cinema4D. It'd suck to have to do it all again but I'd understand if that was required. 

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    You should b able to export your .c4d scene to .obj ,  .fbx or alembic without without any problems. 

    Whether your choice of CAD software can import /export that file type is another matter. 

     

    I'd post on some CAD forums for additional feedback. 

     

     

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    Unfortunately the prototype "Betwixt" plugin that did render booleans in C4D is no longer in the Cafe's download section. I don't have a copy of it any more. Only worked with older versions of C4D hence the reason I think I removed it from the downloads. Anyone still got it?

     

    Modo by the way does render booleans.

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  • Thanks for the feedback southpaw & 3DKiwi! 

     

    So here's what I decided to do since I do not have any experience in CAD and was unable to get an Engineer who made my model to assist in this project:

    1. I created two primitive square objects to use as my cutting planes to separate my model into two halves. I labeled them "side one, side two."
    2. I created a bool, and nested a single object from my overall model under it to act as "Object A"
    3. I then placed the primitive square "side one" under the bool as well to act as "Object B"
    4. I then went into the bool, set "A subtract B and/or A intersect B."
    5. Selected the bool, primitive square, and object form my model and "connected objects and delete." 
    6. Repeated this with "side two" of the other primitive square object. 
    7. Repeated this process 1800 times.
    8. Now I have a model perfectly split in half. My main problem is I now have to texture 1800 objects instead of 900 but it appears to work so I can't complain.

    Absolutely something I wish was improved from a feature perspective.

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    36 minutes ago, BLSmith said:

    Repeated this process 1800 times

    Now that's some dedication! Maybe you'll find an easier solution in the future :)

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