Parametric transformation of a ship design not working in Maxsurf

Discussion in 'Software' started by vishal, Jun 18, 2018.

  1. vishal
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    vishal Junior Member

    I have designed Bourbon dolphin's hull in Maxsurf Advanced modeler. But, it is not parametrically transforming. I'am new to maxsurf and don't know things like coherent surfaces and surface fairing. In its manual in Parametric transformation restriction I found "Transformations are applied to visible surfaces only. Surfaces selected should form a coherent model capable of being analysed in Hydromax. This means that care should be to taken to trim intersecting surfaces where necessary and make sure that potential ambiguities such as multiple openings in the hull are resolved."
    Below attached file is my .msd file it has curves and surfaces. Can anyone please tell me what is wrong in my design.
     

    Attached Files:

  2. bhnautika
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    bhnautika Senior Member

    Vishal at a glance you seem to have two hulls in the same space, the editable hull has inconsistencies between surfaces that make up the hull, the “surface stiffness” is different, some have curvature others don’t, so they cannot be joined as one.
     
  3. vishal
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    vishal Junior Member

    One is generated trimesh from markers and other surfaces I created from curves. Can you tell me how should I design it from markers. I watched a video there he divided curve into parts and created different surfaces on them. Should stiffness has to be same ?
     
  4. bhnautika
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    bhnautika Senior Member

    The number of points and their stiffness must match to join, other wise the edges are different. Always ask yourself do I need so many markers and stations to recreate the shape? You have some markers only 50 mm apart.
     
  5. vishal
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    vishal Junior Member

    Okay! Yeah they are so close as they have to define curvature precisely as given in the offset table.
    Each edge curve is used in 2 adjacent surfaces . can you elaborate how stiffness has to be given ??
     
  6. vishal
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    vishal Junior Member

    I'am sorry if I'am asking so many doubts but as I'am new to maxsurf and surface modelling.
     
  7. TANSL
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    TANSL Senior Member

    The first rule to be able to create models successfully is to make things (surfaces) as simple as possible.
    The second thing that, in my opinion, must be taken into account is that it is very difficult, or at least extremely laborious, to get the surfaces of MaxSurf to go through the mark points. Nor is the triangular mesh created with mark points totally reliable. Therefore, many MaxSurf users use other applications to create the 3D model.
     
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  8. bhnautika
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    bhnautika Senior Member

    Vishal the surfaces doesn’t match the markers so you may want to rethink the accuracy you want, perfect or best fit, the surface stiffness in the transverse and the longitudinal directions are 2 (linear) on some surfaces, so are not curved but are flat planes between points.Also some of surfaces are transposed (columns and rows are reversed)
     
  9. vishal
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    vishal Junior Member

    @bhnautika I just want a best fit to calculate hydrostatic data of differently scaled ship. Which stiffness should I use ?
    @TANSL I previously used rhino for modelling but it's model was also not scaling properly. maybe I made some mistake in its model.

    Which is preffered? making curves from markers then surfaces from curves or surface directly over markers ??
     
  10. TANSL
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    TANSL Senior Member

    I'm not sure, it depends on your abilities in each case, but I think it would be more comfortable to draw curves and use them to generate the surfaces.
     
  11. vishal
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    vishal Junior Member

    @TANSL How stiffness should be choosed ?
     
  12. TANSL
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    TANSL Senior Member

    See attached picture
     

    Attached Files:

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  13. bhnautika
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    bhnautika Senior Member

    Vishal the amount of stiffness you can choose depends on the number of points in a column or row. Always try to use the least number of points to get the shape you need.
     
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