Tutorial: Crafting a Military Backpack

Eugene Vasjukov prepared a step-by-step tutorial on creating a military backpack prop inspired by Tom Clancy’s The Division. Software used: Marvelous Designer, ZBrush, and Substance Painter.

Inspiration

The main inspiration for this backpack asset was Division. My goal wasn’t to just use an original concept from the game and make it into 3D. I wanted to make my own piece but in the style that Division game has. So I took a few screenshots of the backpacks in the game, then went to Pinterest and started researching military backpacks to understand more about this prop.

Marvelous Stage

I didn’t have any experience in simulating backpacks in Marvelous, and on YouTube, there aren’t many tutorials for them. Luckily, I managed to find one that suited me perfectly. A shout out to the author of this video, I basically followed it step by step:

My backpack was a bit more complex. It should have had a couple of pockets on the sides and 2 big pockets with rectangular and square shapes in the front.

To connect the parts that were on top of the base I created an additional piece with the shape of the future pockets and sewed them to it (later on, I realized that I could have used internal polygon/ line). I didn’t apply any materials to the base shape and the pockets. At this point, the job in Marvelous was done.

Note: I exported the base shape of the backpack without pockets. I exported them separately so that I could simulate them in higher res than the backpack to get better folds.  In my case, it would take too much time to simulate all the parts at the same time because my pc is not that powerful. Also, I quadrangulated my mesh by right-clicking “Quadrangulate” in the 3d viewport.

ZBrush Stage

Now that the base shape with some folds is made it’s time to add some details in ZBrush.

First of all, I duplicated the mesh, “Autogrouped” all parts, and then separated them to work on each part manually. Then, I ZRemeshed all parts to get lower polycount and projected all the info from the Marvelous mesh to the ZRemeshed one.

Now let’s add some stitches. I prepared a variety of them. There are small and big ones and stitches that are inside.

Next step is to give the mesh additional fabric parts for a more realistic feel, like the part on the big top pocket. You can put there something like a small pocket for ammo.

Military backpacks should also have some belts to hold stuff, so I decided to add them in the front (on big pockets), on the sides (on small pockets), and on the back stripe. That way you will add more details and again you can put something there for more realism. The backpack is starting to get quite handy.

For the belts, I used the brushes by Fedor Losev which you can buy right here. He also has all sorts of military belts and buckles.

Next, I added the zippers by using default IMM brush. I made a quick tutorial on how to make a specific path when using IMM brushes.

Note: I deleted all zipper locks because they had too many polygons and I wanted them to be separate models. Later on, I retopologized one and cloned it many times. And the zipper lines will be baked on the normal map.

To make things look even more complicated, I modeled a few pockets with and without ammo trying to make them as low as I could. I started in Maya to make the low poly, then went to ZBrush, dynameshed and drew some stitches on top. You might notice that there is a cotton noise texture. I added that to make my normal bake even better and more detailed. When I did a test bake, the curvature map was baking too long. When it finished baking and when I dropped a random material with a dirt mask to test the result I got a lot of noise because of that curvature info that calculated the noise from ZBrush. Basically, I was getting a lot of pixels instead of dirt spots. That’s why I didn’t use this method (adding noise in ZBrush). Later in Painter, I just used a tile cotton texture.

To make a rope I used ZSpheres a made a path by adding more spheres on the corners. I did only 1 side, then ZRemeshed with parameters around 0.3-0.2. If you put 0.1 you might end up with too low poly version. Then mirrored, sewed together and tweaked to achieve that rope pattern path. Also, I modeled buckles.

The ZBrush part is almost over. In the end, I made the scissors asset to bring more interest and a stamp with the Division logo in the front and the back.

Note: To make all minor details like buckles, belts, and scissors I used Maya. I just modeled them, that’s all.

Before making the low poly I colored all parts for ID bake in order to make the texturing process much easier. It’s very simple, just click on “Colorize” in the “Polypaint” tab (in ZBrush), then select a color and press “Fill” in the “Color” tab which is in the top menu.

The final high poly looked like that:

Low Poly Stage

For the low poly, I used Topogun. I tried not to make it too low to keep all the folds and make an even topology. (P)

I made 3 UV sets to optimize:

• for the backpack itself
• for the pockets (I might reuse them in the future, so it’s very comfortable when they all share 1 UV set)
• for the belts which I tiled (they were just rectangular scaled up stripes)

This way the texture would weight less. All the buckles, as well as the little details, are mirrored.

The overall polycount with the pockets and the scissors is 12,570 tris.

Substance Painter Stage

I will be showing the texturing process using the example of the brown backpack (I made 3 skins in total, just because I like to experiment).

I started with baking. Since I had a lot of meshes I used “By name” option. I baked twice a resolution, so if the backpack is 2k, I baked 4k to have a better, less pixelated result, especially for normals. I will export it in 2k though.
First, I filled the whole backpack with Fabric texture, then added Fabric Woodland on top. It gave me a camouflage pattern (30% opacity) + a few wrinkles (20% height) and a smart mask material. It’s very powerful!

Now it’s time to get that ID map that was baked before. I selected zipper, used Basic metal material and tweaked it a bit. Then, I again used the brown Fabric on the stripes and another Fabric on the green parts for color variety. Next, I filled the top part with 2 more materials with less UV scale.

Now when all the meshes have basic colors and texture it’s time to add some dirt. I used “Fabric UCP used” material but I only took the dirt layer. I played with parameters and lowered the opacity to 67%.

After that, I manually painted the scuffs by using a brush with 80% opacity and yellow color. The layer itself was set to 69% opacity.

On the belts, I used tile texture “Fabric Cross Curved”, the scale was set to 12. You can find this texture in the Procedural folder in Painter.

For the holders, the pipeline is the same. For ammo, I used “Steel Tank Painted” material plus added grunge (Rust Coast) and a bit of metal manually.

Render Stage

I rendered the backpack in iRay.

T0 summarize, the backpack has:

• 12,570 tris (6530 polys)
• 3 UV sets:
  1 – backpack 2048
  2 – belts, ropes 1024 (tiled)
  3 – pockets 1024

Eugene Vasjukov, 3D Artist