Bootcamp: Gravity Sketch

In our second look at this VR modelling app, we explore how it has improved with the addition of subdivision modelling

Find out more about this VR tool

Since we last delved into Gravity Sketch, the design and modelling tool for VR creatives, it has both gained ground in the VR creative space and become even more popular with artists around the world.

However, a new feature has made Gravity Sketch the first application to warrant a second appearance in the Bootcamp series. Namely, the inclusion of a subdivision modelling workflow to complement the existing NURBS and spline workflow.

While not every object that has been created in Gravity Sketch can be used to create a subdivision object, the available ones are a good start. The most basic is a single polygonal plane, which can be extruded either along an edge or by polygon face to create more geometry. Edge and polygon loops can also be selected and extruded.

Vertices snap to each other to create new geometry and seal holes. If symmetry is being used, vertices snap to the centre line. Just remember that symmetry needs to be on from the start of a modelling session for it to work.

There is also a set of three new tools available for polygon modelling. These allow an artist to smooth out geometry, cut new edges and merge different objects into a single surface. These tools make it very straightforward to create basic characters and vehicles, and for many artists could provide a more straightforward workflow than initiating modelling in a standard 3D application.

Subdivision smoothing is easily turned on and off to view a polygon mesh. And while selective colour cannot be applied to individual polygons as yet, colour can be added as with every other object in Gravity Sketch.

The new subdivision toolset has elevated Gravity Sketch into a unique, friendly modelling tool that provides a fresh, intuitive and affordable way to get artists of any experience level to start modelling. Let’s explore what it can do.

01 START SKETCHING

While the subdivision and polygon modelling toolset is a great new feature, that does not mean the existing Gravity Sketch workflow should be abandoned. The sketch brushes should still be used to quickly form a quick 3D sketch that can allow the artist to get an idea of the volume very quickly. Keep the sketches to a single Gravity Sketch layer which can be hidden or shown at various transparency levels as desired through the modelling process.

02 CREATE A POLYGONAL OBJECT

While a couple of the pre-existing NURBS tools like surfaces can be converted to a polygon/subdivision surface, if it is a new scene, it is potentially best to start working with a single plane, with symmetry already selected. To do this, go to the Primitive menu and select Plane. Make sure the subdivision rounded cuboid icon in the top right of the primitive plane is selected. This greys out the primitive objects Gravity Sketch cannot use to make a subdivision object.

03 WORK WITH A SUBDIVISION OBJECT

The workflow for subdivision objects is similar to that of manipulating any object in Gravity Sketch. Tap the top edit button on the secondary hand to switch into a view that allows the artist to manipulate points, edge and polygons. If symmetry has been turned on, vertices will snap to each other along the line of symmetry, creating a unified object and making initial modelling easier in Gravity Sketch than it is in many other 3D applications.

04 EXTRUDE EDGES AND POLYGONS

Extruding edges to create more geometry is simple in Gravity Sketch. Select an edge(s) or polygon(s), then a single click on the primary controller’s trigger pulls out a new edge or polygon. Vertices will snap to nearby points and seal edges. With the Auto Select Loops tool selected from the tool palette (visible on the secondary hand in edit mode), Gravity Sketch can select plausible edge loops and extrude a strip of polygons with one click of the trigger.

05 TOOLS FOR POLYGONS AND SUBDIVISIONS

The subdivision toolset is accessed by clicking on the lower button of the primary hand, which has the icon of a brush and hammer when in editing mode. The sphere with the stick is a smoothing tool, which smooths out point position – remember to scale the scene in Gravity Sketch rather than the smooth tool itself. There is also a knife for cutting new edges into a polygon and a merge tool which can combine separate polygon objects in a single layer.

06 ACTIVATE SUBDIVISIONS

In the edit palette toggle the Off/on button under Subdivision Level. There are three layers of subdivision smoothing available. If edges are too smooth, edge loops can be easily added by singleclicking the trigger on the primary hand on an edge, which will then make an edge loop if there is a plausible polygon loop available. With 'Auto Select Loops' selected, an artist can manually slide the new edge loop to make a harder corner. •