As mentioned earlier in Bender, Product Design #1, I felt that compared to general CAD programs, Bender3D requires additional settings for scale management and history function (non-destructive modeling), or lacks materials to introduce easy methods. Therefore, I would like to mention how to work in a CAD method in Bender3D.
1. Reference Positioning
Among the sketches drawn in #1, the sketch to be modeled is placed in the proportional sketch drawn earlier. When modeling, it is good to design by comparing the size and proportionality of surrounding objects with the picture you thought of when sketching.
Cut and replicate the idea sketch with the selection tool.
Scaling the 2D idea sketch and placing it in the location to be modeled. And the sketch also gives transparency for reference in modeling.
I work by imagining whether the actual scale and ideas are similar and what they will be like in the surrounding environment.
2. 3D Blockout
The rough placing of 3D Primitive chunks for design formations is called Blockout. (3D Artist’s Blockout concept explanation) : https://youtu.be/F7frk_7P00o, When rendering a car Blockout : https://youtu.be/4Q4rh1gFWGg, In product design rendering Blockout : https://youtu.be/03IrOGkbaZc) Blockout is a basic work to find the most similar formations when the idea you thought of in design is in 3D.
Once the primitive, which was intuitively blocked out in the 3D space, has been determined to some extent, the dimension must be abstracted and entered (161.2341mm => 160mm) to be machined or modified to a numerical value for the convenience of communication
Place the Primitive Object configured through Blockout in the Rough Scale sketch and manually enter the numerical value in the Transform window
Move the composition of the form freely and quantify the composition you like and the position & scale.
3. Detail Modelling – Bevel (CAD: “R Value”, Fillet, Fillet Edge)
In CAD, the Round operation of finishing the edges is one of the important parts. For Blender, a job called Bevel replaces CAD’s Fillet operation. Bevel can also directly modify the mesh in editing mode, but using a function called Modifier, you can perform tasks that are easy to modify in a non-destructive format without modifying the direction of the mesh.
A. Adjust Blender3D like as CAD tool
The basic settings in mesh modeling differ from those in CAD tools, requiring object-specific configurations. (Upon modification and saving as a startup, the default setting makes it conveniently accessible for subsequent use.) For instance, Face Normals, which might deviate from the direction faced by the mesh structure, are set by default to allow free adjustment of the direction of the face (Face Normals) according to the user’s preference, disregarding the model’s face direction. In product design, to ensure that the shape direction of the mesh and face aligns with the actual direction of the surfaces in reality, it’s necessary to enable the ‘Auto Smooth’ option. This automatically adjusts the face direction (Face Normals) to match the Mesh Face direction based on the angle of the surface.
An example of utilizing the default features in Mesh Modeling tools like Blender – in Guilty Gear 3D models and animations, adjusting Normals enables them to appear beautifully from various angles rather than merely forming shadows or displaying based on the face’s structure : https://youtu.be/J5YfZwzARNo
In Edit Mode, select all faces, then choose ‘Shade Smooth’ in the Face menu. Go to the Properties panel, navigate to the Mesh Data tab, and check ‘Auto Smooth’ under Normals. Keep the default setting (30~60 degrees) and make adjustments while observing the face states.
B. Bevel Modifier
For non-destructive Bevel (Fillet) operations, let’s start by explaining the concept of Modifiers. Modifiers aren’t about manually shaping the model into a Mesh (Vertex, Edge, Face) one by one; instead, they allow simple numerical adjustments to reflect changes on the mesh and can be reverted at any time (Modding?). In the Bevel Modifier, the default setting applies the bevel to all edges. The ‘Amount’ parameter allows precise control over the amount of Fillet (Bevel) applied to the specified model, measured in millimeters. To support a low-level (GPU & CPU-friendly) 3D Modeling Pipeline, ‘Segments’ enable adjusting the number of face operations representing ‘R’ per object, focusing on optimization. This concept enables real-time, photo-realistic quality modeling in software like Blender or game engines.
‘Segment’ is an element not commonly found in traditional CAD programs during modeling. However, in CAD tools like Siemens NX, Solidworks, or Rhinoceros, when significantly magnifying ‘R’ (Fillet Edge), angles become visible. While it varies between programs, it’s notable that some may automatically adjust Segments based on graphic card performance without offering explicit options.
When set to Shade Smooth, regardless of whether the Segments value is 3 or 9, the surface of R appears smooth. However, examining the edges reveals that R is segmented according to the number of Segments set. The ‘Amount’ parameter allows precise adjustment of the desired R to a specific value measured in millimeters.
C. Bevel Weight (Non-destructive variable fillet edge.)
To provide variable amounts of R (in mm) to each edge within a single object (common in CAD), Blender offers a feature called Bevel Weight. However, Bevel Weight doesn’t operate in millimeters; instead, it requires using the Modifier’s Amount, dividing it between 0 and 1. This adjustment is for optimization purposes.
In Edit Mode, selecting an edge and assigning an abstract Weight Value allows for real-time modifications in proportion to a freely adjustable fillet within a 6 Faces Mesh. This enables observing and editing changes in real-time. Additionally, addressing variable Fillet (R) corner issues, crucial in CAD, can also be resolved in Blender through the Geometry > Inner option using Arcs.
Assigning variable Corner Rs to edges allows maintaining a consistent ‘exact’ R even while freely modifying surfaces. This feature enables the author to experiment and create diverse shapes. While this might not be noticeably impactful in a square model, in complex models, the strength of Modifiers becomes apparent when modifications are made to chunks while the designated Fillet on edges remains unchanged.
Rendering through advanced non-destructive modeling techniques and methods to maintain precision as discussed in #3.
