1. Difference between Solid Modeling and Surfacing
- feature : Principle
- Solid Modeling : Made from solid volume
- Surfacing : Made from a set of ultra-thin planes and surfaces (Zero Thickness)
- feature : Usage
- Solid Modeling : Mechanical parts, structures, precision sized parts
- Surfacing : Car bodies, electrical products, water bottles, toys, medical design
- feature : Complexity of shape
- Solid Modeling : Suitable for square, straight, and standard curved shapes.
- Surfacing : Ideal for freeform shapes, complex curves, and surface convergence that require detailed control.
2. The main concept of creating a surface (Surfacing)
Modeling with textures requires precise control of curves and planes to create smooth surface connections.
2.1 Creating Driving Curves
The heart of texturing is defining the shape's direction with precise 3D curves, which act as boundaries or guides for creating the surface:
- Sketching 2D/3D: Drawing curves on a plane or in 3D space.
- Project Curve: Projecting curves from two-dimensional planes onto each other to create a three-dimensional curve.
- Spline: Using free-form curves (Spline) to finely control shapes by adjusting control points (Control Points).
2.2 Basic commands for creating surfaces
These tools take the created guide curves and convert them into a surface:
- Extruded Surface: Stretches a curve or 2D shape in a straight direction.
- Revolved Surface: Rotates a curve around an axis to create a surface that is symmetrical around the axis.
- Swept Surface: Sweeps a profile along a specified path.
- Lofted Surface: Creates a connecting surface between a set of curves (Profiles) that are on different planes.
- Boundary Surface: The most powerful tool, often used to create complex surfaces that require full control of direction by defining boundaries in two directions ($U$and$V$)
3. Surface Quality Control
When designing complex shaped products, especially in the automotive industry or premium products, a surface quality control called Class A Surface is required.
- Class A Surface: Refers to a surface that is visually perfect, smooth, free from seams, wrinkles, or reflection distortions. It is often used for exterior surfaces that are directly seen and touched by the user.
- Continuity Checks:
- G0 (Position): The surfaces touch at the edges, but not in the same direction (broken edges).
- G1 (Tangent): The surfaces touch at the edges and have the same direction (smooth, but the reflection may be slightly angled).
- G2 (Curvature): The contact surfaces at the edges have the same direction and the same curvature at the point of contact (smoothest, continuous reflection).
3.1 Surface Analysis Tools
Used to check and improve the quality of the surface:
- Zebra Stripes: Displays colored stripes on the surface to check for continuity of the reflection. If the zebra stripes are deflected or angled, the surface is not smooth (G2).
- Curvature Analysis: Displays colors based on the degree of curvature to reveal areas with excessive curvature or abnormal bends.
- Draft Analysis (Slope Analysis): Check the required slope angle for removing the part from the mold.
4. Surface treatment and final steps
1. Trim and Knit/Sew: Use the Trim Surface command to cut off excess surfaces, then use the Knit Surface or Sew Surface commands to combine the cut surfaces into a single surface.
2. Thicken/Offset Surface: Once all the surfaces are fully connected, the Thicken command is used to add thickness to the surface and turn it into a production-ready solid model.
Creating surfaces is an advanced skill that requires a deep understanding of mathematics, geometry, and design to create products that are aesthetically pleasing, sleek, and in line with manufacturing engineering principles.
Main techniques:
- Surfacing , Surface Work , Surface Creation , SolidWorks Surface , Solid vs Surface
Body type:
- Organic Shape , Freeform , Freeform , Complex Shape , Curvature
Surface quality:
- Class A Surface, G2 Continuity, Zebra Stripes, Curvature Analysis
software:
- SolidWorks , Advanced CAD
Usage:
- Product design , automotive design , mold , curvature control
#SolidWorksSurface #Surfacing #OrganicShape #Freeform #Surface work techniques #complex product design #G2Continuity #ZebraStripes
Here's the first image, contrasting "Solid Modeling" (showing a blocky, mechanical part) with "Surfacing" (showing a sleek, curved product like a car body), emphasizing the difference in design approach.
For the second image, let's illustrate "Key Surfacing Tools" by showing a SolidWorks interface with highlighted tools like Lofted Surface, Swept Surface, and Boundary Surface being used to create a complex organic shape.
Now, for the third image, let's visualize "Surface Quality Control" with a focus on "Zebra Stripes" analysis on a smooth, curved product to show how surface continuity is evaluated.
