What is SubD (Subdivision) Modelling?

Introduction

Subdivision modeling is a digital 3D modeling technique used to create clean, scalable, and highly detailed models that render beautifully. One of its key advantages is rapid topology generation, enabling artists to quickly develop complex and efficient meshes from simple base topology. This method is widely employed across industries that utilize digital artistry, from animation and gaming to product design and visual effects.

Subdivision modeling offers creators a more straightforward and efficient way to produce intricate organic shapes. For instance, it allows for the creation of realistic skin textures and ensures the smoothness of the generated models. Its effectiveness was quickly recognized, leading to its use in feature films such as "A Bug's Life" and "Toy Story 2".

When converting NURBS to SubD, you cannot revert back to NURBS. You can however continue to edit the mesh in GS or in any other third party software such as Maya.

The launch of SubD builds on the existing Gravity Sketch toolkit, making it the first VR software with a powerful combination of modelling techniques — polygon mesh, NURBS, and SubD.

What exactly is SubD?

SubD provided the creators with a simpler, faster means of producing highly complex organic shapes, for example it helped give Geri a more realistic skin texture and guaranteed the smoothness of the model. The power of SubD was quickly realised, resulting in its use in feature films such as “A Bug’s Life” and “Toy Story 2”.

I’m not an animator, is it still going to benefit me?

Absolutely — the beauty of the integration of SubD provides users with a seamless experience, users can sketch as usual but now edit their strokes in a completely new way. Existing users of Gravity Sketch can convert their models to SubD for further shape and form exploration.

SubD has the potential to enhance the creativity of all types of designer! For example, automotive designers will be able to create entire vehicles from one continuous surface and move components around without losing continuity of surfaces, enabling them to quickly produce a high-quality surface. Additionally, footwear designers will have the ability to produce smoother complex meshes using SubD, which more realistically follow the curvature of a foot.

“…SubD in Gravity Sketch is a big deal for automotive designers because it offers even more of what makes Gravity Sketch so great, to begin with — creativity and control…”

Artwork: Glen Southern, Digital Sculptor & 3D Modeller at SouthernGFX

Ok, I’m interested. Tell me more…

The combination of Gravity Sketch’s intuitive user experience and the power of immersive VR technology allows even novice designers to explore SubD creation. Moreover, experienced designers can create intricate models with ease and gain a deeper understanding of the creation’s form.

“…Converting surfaces to SubD in Gravity Sketch is a more approachable way to learn SubD modelling…it is easier for designers coming from more traditional modelling…”

Adding SubD to Gravity Sketch enhances its capabilities as an integrated workflow tool, since users are able to export SubD models as OBJ and FBX files, with the base mesh preserved, for use in standard industry tools such as CAD or rendering programs. The aim of this is not to position Gravity Sketch as a replacement for CAD, but to reduce restrictions on creativity by offering users the opportunity to model at an additional level of precision.

Most importantly, existing and future users benefit from the added flexibility and greater level of control over their models that SubD offers without sacrificing the intuitive UX that Gravity Sketch continues to prioritise.

“…Our priority is producing great user experiences while simultaneously building tools that can be used in a professional workflow. This is a challenging task; from day one we had ambitions to include SubD modelling in an elegant way, harmoniously coexisting with NURBS and a seamless user experience. Our aim was to create a tool that would hide the mathematical complexity, allowing users to freely explore shape and form, maintain creative flow, and ultimately have a digital asset that is usable in the next phases of their design workflow…”

Artwork: Sosa Fresh

SubD in Gravity Sketch

Check out the current feature set below:

• Converting imported OBJ to SubD: import OBJs and use them directly as SubD objects

• Exporting SubD mesh for use in other software: users are able to export SubD models as OBJ / FBX with the quads preserved for use in standard industry tools e.g., CAD programs

• Edge Loop creation: adds a full loop of vertices around the mesh

• Face and Edge Loop selection: select and extrude entire rows of edges, vertices and faces

• Smoothing Tool: averages a selection of vertices to create a smoother shape, useful for organic modelling

• Edge Cut tool: enables users to create faces with any number of vertices, to allow for tighter control over the topology of the mesh and create complex shapes

• Constrained Movement Tool: face movement is restricted along an axis, enabling users to easily create perpendicular shapes for blocking out models

• Soft selection: enables users to smoothly deform sections of a model by selecting a set of vertices within a sphere of proportional influence

• Merge SubD objects: connects two objects that are created separately

• Primitives and editing as SubD: 6 primitive shapes that are editable in SubD

• Edge extrusion via vertex grabbing: extrude edges on a subdivision object by grabbing adjacent vertices