Making My Models

Game art is really not one of my strong suits. I mean, don’t get me wrong – I think Hypergate looks pretty good. But first and foremost, I consider myself a programmer, not an artist.

Here’s a 3D model I built back around 6 years ago at the beginning of Hypergate’s development. (I couldn’t find the original textures.)

old-model-1

This was originally an enemy fighter.

 

Not bad, but I think my more-recent Hypergate art looks better:

ship-render

The Validor A, a new fighter in a future update.

Now, having worked previously with some truly talented game artists during my brief time in the VR industry, I know that my art skills don’t come close to theirs. But, I recognize that my improvements were only possible through lots of practice. And you can learn too.

The goal of this post is to provide a brief outline of my workflow for building and texturing 3D models for my games, including Hypergate. It’s a relatively simple, methodical approach that works for me.

Our case study will be the Validor A, the new fighter shown above that will be part of a future Hypergate Content Update. The focus here will be on high-level steps, not artistic design. This is also not a technical tutorial on modelling.

So, let’s get started.

1. Build the Model Shape

The first step – and really, the hardest – is shaping the model. Blender is my tool of choice. It’s free, has great community support, and is regularly updated.

I usually start with a cube and extrude. I’ll sub-divide a few faces and add loop cuts here and there. My approach is to first focus on the large details. My space ships tend to have big wings, gun turrets underneath, a cockpit, and a few greebles on top or below. I’ll start with the large pieces like wings and the nose to get the shape figured out. As always, I’m prepared to use Ctrl-Z as I iterate. The Mirror modifier in Blender is a great way to ensure that my design is symmetrical.

bare-model

Once the wings and nose are worked out, I’ll shape the cockpit. I’ll add greebles on the wings to aid the appearance of appropriate scale. This can be done using the Extrude command. I’ll extrude cylinders for turrets or antennae, and shape boxes into fins. Cylinders work great for rear thrusters, too.

2. Add Seams

Seams define edges where you want to cut your mesh when performing texture unwrapping. Think of it like slicing up a stuffed animal or an orange with scissors: if you wanted to paint each segment of the animal or fruit on a flat canvas, where would you cut to get the flattest and easiest-to-paint segments? The red lines in the wireframe image below show the seams.

seams-model

A rough starting guideline is that I’ll usually want to add seams on the natural sharp edges of my model. This minimizes the texture distortion and provides a bit of robustness if I’m going to use a lower-resolution texture. Of course, there are exceptions, and I always end up adding seams elsewhere as required.

3. Unwrap

Unwrapping is an iterative process. After adding seams, I make sure I’ve done it right by doing a simple unwrap and viewing the resulting UV islands.

uv-islands-model

Enabling “Stretch” for “Angles” in the right-hand Properties toolbox helps to visualize distortion.

Chances are, I may need to add a few more seams here and there and repeat the unwrap process to eliminate distortion. I miss seams accidentally on my first try all the time.

4. Adjust UV Islands

After I’ve unwrapped the model, I’ll apply a simple diffuse texture of a checkerboard with lorem ipsum text to my model. The checkerboard helps visualize scale and the text indicates direction. (Often my textures will include text like safety stickers.)

I’ll now translate, scale, and rotate the UV islands until I get the appropriate levels of detail for each component of the ship. Often I’ll group related UV islands together to make texturing easier later on.

In rare cases, I might need to go back and add more seams and do some re-unwrapping. “Pinning” UV vertices is very useful for ensuring that vertices I know to be correct won’t change during subsequent unwraps.

5. Exporting UV Layout and Texturing

My image editor of choice is GIMP. For small fighters in Hypergate, I’ll usually export a 2048×2048 image of my UV islands from Blender for texturing, although the final in-game textures end up smaller than this for reasons I’ll explain later. For larger objects like cruisers, I’ll usually export 4096×4096-sized UV layouts.

In GIMP, I start by adding a base colour layer (off-white, in the case of the Validor A). I colour individual UV islands, add some panelling, warning stripes, service panels, warning stickers, arrows, some text, vents, rivets, LEDs, and engine glow. I also add dirt and scratch layers. The “Layer Mask” feature in GIMP is a great way to add the appearance of worn-out paint or labels. This becomes the diffuse texture of the model.

uv-texture-mapping

I’ll also export emission, specular, and normal maps. These are just exported versions of the diffuse texture with the appropriate layers turned on or off, and further separately tweaked. The “Normal Map” plugin for GIMP is how I build my normal maps.

6. Applying Final Textures

By now, I’ve got diffuse, emission, specular, and normal maps for my model. In Blender, I’ll replace the original checkerboard material with a new one that uses these four textures. I’ll create four “Image Textures” in the “Texture” tab, setting their “Influences” appropriately.

7. Final Optimizations

2048×2048 is a pretty large texture size for a 10 meter fighter travelling at a couple hundred meters per second. This can eat up valuable GPU memory, takes longer to load from file, and is simply just an unnecessary level of detail. For small fighters in Hypergate, I usually export the following image textures:

  • Diffuse: 512×512 RGB PNG
  • Emission: 256×256 Greyscale PNG
  • Specular: 256×256 Greyscale PNG
  • Normal: 512×512 Greyscale PNG

This generally gives good results in terms of both level-of-detail and image sizes. Larger or slower objects are assigned larger textures to maintain good visual quality.

The model itself is exported as a Wavefront .OBJ file. I’ll export several levels of detail for each object. (The Decimate modifier is really useful here.) The small fighters typically have the following levels of detail, although it varies on the model:

  • High quality: 4,000 – 6,000 triangles
  • Medium quality: 2,000 – 4,000 triangles
  • Low quality: 1,000 – 2,000 triangles or less (I just set the Decimate modifier to the bare minimum that maintains the general model shape)

So how long does this entire process take? It depends. When I rush myself with this kind of work, it usually results in poor quality and more mistakes. A ship like the Validor A might take me about 2-3 days’ worth of full-time work, from start to finish.

I hope that this guide has been somewhat useful. Like I said, it is rather high-level. Comments are more than welcome if you have suggestions or would like more details on a particular step.

GN

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