Model a cyber weapon in Gravity Sketch
Let’s take Issue 265’s arachnid mech and give it some high-tech weaponry
Design high-tech weaponry in VR with Glen Southern’s guide
In Issue 265 we designed a large mechanical spider that looked like a JCB from the future. This month is all about futuristic weaponry and I decided to augment the mech we built with some rocket launchers and a couple of powerful arms loaded with munitions. I will often get a job where I have to design the same character or vehicle but give it different add-ons or enhancements. This vehicle/ mech will go from a basic loading machine to something a little more sinister and ready for action in the future.
We can use the same Gravity Sketch core tools including the older spline-based tools and some of the newer features, like subdivision modelling and things like the revolve tool for the rockets. I will make the base model available so you can follow along and create your own weaponry using these same skills. As with the first tutorial, a great way to start a design in VR is to use a sketch layer and simply draw out your idea before diving in and using the modelling tools. From there we can make a ‘volume’ model, which is a simple block of geometry to represent where we will add the final parts.
01 PREVIOUSLY…
The project in Issue 265’s tutorial focused on making a mech spider with some very cool legs and mechanical moving parts. The basic premise was that the design was an industrial robot with specific loading and maintenance duties. Sometimes on a design or concept job I will be asked to try out different ideas or versions, so that’s what this project is about. Same mech, different job. Let’s add some weaponry! We will build on the skills we learned last time, but don’t worry if you didn’t see it, I’ll still cover the basics.
02 START WITH SKETCHING
To begin with, load up the older model. I will make the model available from my website so you can work along with me. We need to start on a new layer (non-dominant hand, blue button, layers). Add a layer, and while we are there, lock the other layers so we can’t affect the base model. This layer is to be our sketch layer and it is where we will work out all of the dimensions and scaling. Use the ink or stroke tool from the tool panel on your non-dominant hand. Either tool is great for sketching in this way.
04 VOLUME TOOL/LAYERS
Once you have roughed out the sketch lines you can make a new layer and start working out the volumes of the new parts. The rocket launcher needs to have some sort of attachment to the main body, so use the volume tool to show how that might work. Don’t think about detail, rather focus on the shapes that make up your idea. Large shoulders and biceps mimic a creature, then add large forearms to carry the rockets that look like fingers. Make sure you keep turning the model to check that the volumes are looking good from all angles.
03 THE BASIC FORMS
Keep your sketching fast and loose, exactly as you would see a pencil artist working. This is about feeling the form and working out exactly where to put everything rather than focusing on any detail. Try to think of it much more as a sketch tool than a modelling tool at this stage. Sketch out a rocket launcher across the back of the mech and just indicate two arms to carry more payload.
05 ARM JOINTS
Make sure that the joints are in the correct place. With the forearm, ensure there is a circular joint at the base to allow it to rotate as a normal arm would. You can also use the revolve tool to make some nuts and bolts to add detail to the joint areas. You can also use the stroke tool to add pipes at a later stage to make the joints look more visually appealing.
06 REPOSE ARMS
Once you have the arm blocked out with the volume tool, start to think about the position and posing of the arm. Start at the shoulder and move it into a position that looks good on both sides of the model, then rotate the forearm so that the rockets are facing forward and it looks like a powerful pose. Move around the model in VR and check that the arms look good from the front, side and top. Ensure the forearm looks large in comparison to the bicep area, as we want it to carry the rockets and look imposing from all angles.
07 REVOLVE ROCKETS
The main weaponry on this creature is going to be rockets, so we will make a large central rocket on the back of it and banks of smaller rockets both at the back and on each arm. Start with the central large rocket and call up the revolve tool from the menu on your nondominant hand. Click the revolve tool and change the settings to ensure you are using it in point mode. Half depress the trigger on the non-dominant hand and hover over the centre line until you see a blue line, meaning you are exactly in the middle. Now lay down points and create the shape of the rocket.
08 REVOLVE TOOL SETTINGS
Carefully place points to shape the rocket as needed. Add surface detail by adding points close together and more towards the centre to create ridges and raised areas. Make the rocket taper from the front to about a third of the way down the length, and then finish it as a cylinder by placing points all the way to the very end, which will be embedded in the back assembly.
09 USE MULTIPLE PARTS
You do not have to make the rocket as a single component. You can stop the revolve process at any point by hitting the trigger on the non-dominant hand controller. When you start again you can embed the first point inside the rocket and then bring the next point outside, allowing you to have multiple parts or sections down the length of the rocket. This will help you later if you want to slide a portion of the rocket backwards or forwards if you feel it better suits the render.
10 PLACE ROCKETS
As the large rocket in the centre of the back is the main feature, it is important to place it correctly over the model. Where needed, delete the volumes that were used to lay out the scene – we can always add more in later to add visual interest. Pick the rocket up with your grip on the dominant hand and somewhere in the scene place another copy by using the trigger on the dominant hand. This is now a spare that we can use for the rest of the rockets on the arms and the smaller ones further down the back.
11 HIDE LAYERS
It is helpful to make use of a transparent layer when you are working on something complex. You can lock a transparent layer to prevent you from editing it as you work on a component that is hidden deep inside the model. Lock all the layers that you aren't working on currently, as we will now be detailing quite a few areas around the mesh.
12 SUBDIVIDED OBJECT FOR THE ROCKET BODY
From the primitives menu create a subdivision model cube. Make sure you have symmetry switched on before you do this, and then with the blue button on the non-dominant hand activate the point mode so you can push the points of the cube towards the centre line. This will now allow you to keep the centre of the model across the seam. Using extrude and the split tool, add detail to this area of the model, bearing in mind that we will be adding more rockets on the top of it soon.
13 VOLUME TOOL TO REPLACE PARTS
Next we need to use the volume tool set to planar mode to allow us to make more complex and accurate components that will hold the rocket assembly up. The volume tool is now acting like a laser cutter and giving us sheets of geometry that we can shape as needed to make complex forms. Make sure you use a different material when you want to identify the type of metal that a component is made of. This will be reflected in the software that you export your model to at the end.
14 ADD DUPLICATE ROCKETS
On the back of the model we want to add a bank of rockets in an assembly. Pick up one rocket and use the trigger to ‘fire’ to get a duplicate. Repeat until you have a line of three, then with your Grabber covering all three, repeat two more groups for a total of nine rockets. Make sure that they are in the same alignment as the large central rocket.
15 VISUAL INTEREST
Make several wireframe assemblies that will be used to build the framework to hold all of these rockets. Think of it as a casing that will be used to house all of the rockets, but also it will cast lots of shadows and create visual interest. If needed, add some ‘stroke’ pipes inside and around the back of the rockets to look like pipework that's been used to fuel the rockets.
16 REVOLVE FOR JOINTS
Now call up the revolve tool again and create a series of cylinder components that will be used as the axles or a pivoting mechanism for the whole assembly. Adding these extra components enhances the realism of the design. You can use several materials here so that when it is rendered it will look more interesting – placing steel parts with aluminium for example.
17 ADD DETAILS AND NEW MATERIALS
Now that the back assembly is nearly finished, go in and add lots of details with pipes and more mechanical parts. Take a look at the assembly from underneath and make sure there is lots of visual interest, for example complex wires and electronics coming out of the bottom of the rocket.
18 BULK UP THE ARMS
For the arms we will have three main components. The bicep, the forearm, and the rockets, which are like fingers at the end of the arms. Use the same tools again to create a framework that will be used to bulk out the forearm. Add elements that are repeatable to mimic wire cages and subframes of the arm.
The forearm should be the largest of the three components and be strong enough to hold a large rocket assembly.
19 ADD GREEBLE
There are lots of opportunities to add greeble, which is a way to add visual interest fairly randomly. Create components that are like small nuts and bolts, pipework, cylinders, hydraulics and even small electrical components. Try to work out some sort of joint assembly for where the bicep meets the forearm as this will be a crucial part of the design.
20 NEW REVOLVE TOOL
In the latest version of Gravity Sketch a new revolve tool was introduced. To use this, swipe around your waist area with the grip depressed. This will allow you to use tools on your tool belt and one of those tools is a stick with a circle on the end of it. If you hover it over anywhere that is a joint, you can then use the tool to test how the joint revolves in any of the three different axes.
21 GROUP
It’s important to group each section as you finish it. Hover your Grabber over any area that you want to group together. Hit the purple button on your non-dominant hand to create a group. If you miss anything, cover the new group and the missing parts with the Grabber and hit the group button again. You can also build up larger groups in this way. Group the shoulder and bicep together, then the forearm, and eventually we will add the fingers to the forearm group once we have added the rockets.
22 ADD ARM ROCKETS
We don't need to remake rockets for the forearm as we have already made a set on the fingers. Duplicate the rockets from the back of the model and use these for the hands. We can add a few extra wires and components and they will suffice as our hand components. Add more detail from the forearm to the rocket and make sure it’s consistent with the rest of the model’s design.
23 EXPORT
Once you have the back and the arms in a position where you're happy with the pose, you can then export. Go to the save menu on your non-dominant hand and use the settings for OBJ, and make sure you use the control mesh rather than the rendered mesh. That way you will be getting the unsmoothed models out rather than a very high-polygon version. This can be imported into another program like Blender, Maya or Cinema 4D and used to generate your renders.
24 RENDER
The great thing about Gravity Sketch’s material sets is that they can be used across multiple programs and it allows you to group your model easily by material. Depending on which program you use, simply isolate the components that you want to add materials to and group them. For example, for this model we want all of the grey material as aluminium and all of the yellow material will be a chipped flaked paint.•