Rhino Hull modelling Basic and Useful

Discussion in 'Boat Design' started by bingli, May 24, 2021.

  1. bingli
    Joined: Jan 2020
    Posts: 25
    Likes: 5, Points: 3
    Location: China, Shanghai

    bingli Junior Member

    01 Brief description
    A brief description of this article:

    1. About Rhino
    A powerful 3D modeling software, here it is used to model the hull surface.

    2. About this article
    A concise tutorial that describes how to generate hull surfaces in the Rhino program based on the 3D space hull line generated by a hull line modeling program.

    3. The use of Rhino hull surface
    The hull surface created by Rhino can be used for CFD software for hydrodynamic performance calculations, into professional software for loading and stability calculations, and related designers to make exquisite 3D renderings.

    02 Content
    There are two time consuming process to create surfaces in Rhino : creating space lines and determining facets division. The hull space line used in this article is generated by a professional hull line modeling program. The article does not introduce it, but focuses on the basic operations of rhino hull modeling from the following three aspects

    1 Rhino: basic settings
    2 Rhino: Hull facet division
    3 Rhino: Generate surface

    03 Basic operation steps
    The following are the specific steps

    One, Rhino basic settings

    01 Import and display the hull lines:
    Double-click ① to display the isometric view window only, and click ② to display the zoom setting to adjust the graph

    02 Save the Rhino project:

    03 Set the modeling unit:

    04 Set the middle mouse button:

    05 Set the background grid line:
    Tips: When selecting lines in the graphical interface, the grid lines sometimes affect the selection, and the display should be turned off.

    2. Rhino hull facet division

    There are many different hull shapes, and there is no unified faceting technique. You should first analyze and perform reasonable faceting based on your own ship type, and then model it by area. The flat bottom line and bow outline of this article are obvious. Use these characteristic line to partition the hull.

    The surface in the rhinoceros is a B-spline surface, which is described by two-direction curves (U-direction curve and V-direction curve). The reasonable modeling principle is to select lines in two directions that are as perpendicular to each other as possible to generate the surface. Mesh surfaces and lofted surfaces also have such requirements.

    The hull surface is usually composed of plane and surfaces. This article uses plane commands and mesh surface commands to create ship surface.

    3. Generate surfaces in Rhino

    01 Generate bottom plane
    To create a plane requires a closed plane curve, so you first need to create such a plane boundary curve. Operate as follows: Select the curve ①, ②, ③ in turn, and generate a closed plane curve through the combination command ④

    ①Choose the command to generate surface by plane curve

    ②Select a closed curve, ③Enter or right-click to confirm.

    02 Display surface settings
    It is recommended to create a layer to organize and display the surface, as follows: ①Right click to create a surface layer, ②~⑤Set the material, and choose a color that is easy to distinguish.

    03 Change the object layer
    ⑥Select the generated surface, ⑦right click on the surface layer to pop up the menu, ⑧change the object layer


    04 Render and display
    click button ① to render display

    05 Generate mesh surface
    Tip: The requirement for mesh surface creation is that the U-direction line and the V-direction line intersect each other, but the internal curves of the U-direction line and the V-direction line do not intersect each other.Execute mesh surface command①

    ②It is not recommended to use automatic sorting, the user can select the boundary line according to the U direction and V direction respectively

    U-direction curve: waterline and deck line ③, after the U-direction line is selected, press Enter to confirm and select the V-direction line

    V direction curve (preferably the curve perpendicular to the U line): select station line ⑤, after the V line is selected, press Enter to confirm the completion.

    06 Grid line generation control
    The input parameters control the fitting accuracy of the curved surface. The tolerance of the boundary curve is set to be smaller, and the distance between the surface boundary and the curve is close. In this way, it can be ensured that there will not be too large gaps in the combination of block surfaces.
    Tip: A useful way to check the combination accuracy is to combine this surface with the previous surface after each surface is made. If it can be combined, it means that the boundary accuracy of the surface meets the requirements; if it is not successful, it needs to be renewed. Recreate this surface.

    07 Generate the lower part of the bow

    08 Generate the lower part of the bulbous bow

    09 Generate the rest of the hull

    Key Points and Review
    This article uses a combination of graphics and text to introduce how to use Rhino software to generate hull surfaces based on existing 3D hull space lines. The main points involved are listed as follows:
    1: Basic settings of Rhino software;
    2: Rhino software hull facet division;
    3: Rhino software plane and mesh surface;
    4: Rhino software surface display and control;
    5: Rhino software UV line and its requirements;

    It can be seen from the above steps that if there is a relatively smooth hull space curve, only a small amount of rhino surface modeling skills such as plane commands and mesh surface commands can be used to complete the modeling of complex hulls.
    Benjamin and pafurijaz like this.
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