Tutorial: Modeling & Texturing an Ornate Gun

Ognyan Zahariev was kind to let 80.lv publish his amazing tutorial devoted to the modeling and texturing of the amazing two-barrel shotgun. In this post, Ognyan goes deep into production and shows the little details, which make all the difference for artists. The final model could be used ingame!

Blockout and proportions

STEP 1

I always start with a basic blockout of the model. I strive to use mostly primitives and really simple shapes in order to save time and delve into more detail once I am happy with the result.

At this point I am only concerned with nailing the right proportions which will save me a lot of time later on. Once you start modeling/sculpting all the details it gets so much harder to make major changes in terms of scale without losing a lot of the work you’ve already done. It is definitely not impossible to do it but planning ahead leaves you with more time for creativity and polishing!

Midpoly/Highpoly

STEP 2

After I am confident about the proportions I proceed to creating a clean mid poly model that I use as a base for my work in ZBrush. I keep the topology clean and even in order to avoid any artifacts and stretching in ZBrush.

Then I create some basic UV Unwrap in order to use for any sort of masking and deformations control in ZBrush. You can do this last step inside ZBrush as well – it is up to you.

I put a turbo smooth modifier on in order to make sure that the topology holds the shapes I am going for and I don’t get any nasty surprises in ZBrush.

ZBrush

STEP 3

My first goal in ZBrush is to get the wood carving right. Before I start sculpting away I paint some rough boundaries in Photoshop or DDO so that I get an idea of the scale of the ornaments. I turn this into a mask and use it as a Guide in ZBrush.

Just import the mask as alpha and use the Masking -> Mask by Alpha option

I chose not to use this mask for any sort of deformations but some details would allow for something like this. In my case all the reference for wood carvings on weapons pointed me in the direction of free sculpting instead of using the mask for offsetting geometry.

You could do it both ways but I believe that in this way I achieved a more natural look and better transition from the carving to the flat, less detailed wood parts.

I always use layers and save morph targets! Gives you lots of control over the intensity of all these details and allows you to roll back to a previous version that you liked better after an unsuccessful experiment.

Having that mask as a guide shouldn’t prevent you from improvising! Once all of the details start to take shape one begins to get all these new ideas and learns from the work that’s been put in so far. Don’t be scared to go out of the set boundaries if you believe your model will benefit from it. Remember that the mask is there just to help get a sense of placement and proportions and not to turn into a cage limiting your creativity.

These are the main brushes I used for the wood carving and for most of the details on th shotgun for that matter.

Many of these sort of weapons have symmetrical details on both sides so it makes perfect sense to activate symmetry on these brushes while sculpting away. Do not forget to go in and break up the obvious repetition where the two sides meet and give it a more natural look.

The ClayBuildup brush in combination with a small sized alpha and the Dam_Standard brushes are pretty good for adding dents and scratches.

Use the move brush to break up symmetry in a more decisive way.

Simplicity and level of detail

When sculpting such a detailed model one always runs the risk of forgetting what is the scale of the

object in the real world. This could easily lead to a lot of unnecessary details that you won’t be able to transfer into textures due to resolution limits. It could also take away that manmade look of the prop because no matter how detailed and beautiful such an object may look in the real world, if you look really close you will realize that all these forms start to look a little rough. In my opinion that’s

one of the major ways to achieve realism and good sense of scale. Approach your model like a weapon master would if it was real wood and metal and don’t turn the shotgun hammers into little AAA characters ?

Metal

I approached the dragon in a way similar to the wood carving. I painted a mask in Photoshop in order to get the proportions right and then used the same set of brushes for sculpting.

For the uneven and rusty bits I used the Claybuildup brush in both freehand and color spray mode.

Damage

One of the final touches I added were some dents and scratches. Putting all the different elements of a weapon together is bound to leave some sort of marks like a cavity between the metal elements and the wood. I also wanted the shotgun to have some history. It has been well taken care of but it has definitely seen action which gives it more character.

Low poly

STEP 4

The normal map baked from the high poly model should be enough to hold all these carving details but it is always a nice touch to break up the silhouette here and there which is why I added these small extruded bits sticking out from the overall flat wood surface.

I added a separate piece of geometry for the dragon on the side in order to have better control over the resolution. Generally it is better to keep resolution consistent but in this case bumping it up to give the dragon some extra details didn’t hurt and didn’t lead to any discrepancies.

The final triangle count was around 11000.

Texturing part 1 – Quixel Ndo

STEP 5

I baked a normal and AO map from the high poly and left some of the details such as the grip and the floral metal engraving on the top for NDo.

Doing these in NDo allows for more flexibility and quicker iterations. It also doesn’t require the high poly model to go to extreme number of polygons.

I created masks based on the UVs and the baked normal map and used the following settings in NDo in order to convert them to additional normal map details.

It is a very flexible and timesaving approach for such details.

I used the same approach for the bolts on the bottom of the shotgun.

After successfully generating these additional normal map details in NDo I update the AO map by using NDo’s Map Converter and multiplying the result over the AO map baked from the high poly model.

As you can see I lowered the AO intensity of some areas such as the grip.

Time for texturing the model in DDo!

Texturing part 2 – Quixel Ddo

STEP 6

I start by separating all the major material groups by using an ID map with each material identified by a unique color.

I make sure that I organize the materials in a way that will give me maximum control when tweaking all the different parts of the weapon.

I keep the UVs on top to use as reference when painting directly in 2D mode.

I picked a type of wood that is close to the final result I am going for and created different layers in the albedo and roughness maps corresponding to separate parts of the wood depending on weathering and handling the weapon.

I also bumped up the normal map in places where I was going for a more rough and beaten up look.

I took the same approach for the metal bits and added variation through the use of the albedo and roughness maps starting from something basic like a steel material.

Naturally metal had to be mixed with other types of materials such as rust in order to add that realistic weathering and give the weapon a proper story.

I used dynamask in order to achieve realistic blending between the different materials. It is an amazing timesaving feature but in order to take the texture to the next level I had to go in there and paint some of the details manually as illustrated in the examples below. In this case I had to blend the steel material with rust and dirt and I used the wide range of damage brushes that come with Quixel.

In order to make those metal bits really pop I used a combination of dynamask and manual painting to get some dirt and rust in all the cavities giving them a look that suits a weapon that has been used for many years.

The sand filter of the dynamask is a pretty good start for something like this.

One of the final touches is adding some generic dirt and dust on all material layers without going overboard with it.

RENDERING

STEP 7

The shotgun was created as a realtime model so I chose to present it in Marmoset Toolbag 3.

I made sure that I have a good strong key light in order to make all the normal map and roughness details pop. Placing a rim light to bring out that silhouette is always a good idea for a prop like that.

Activating local reflections and GI makes the various materials behave in a much more realistic way.

Ognyan Zahariev, Senior Lighting Artist at Ubisoft