Steampunk spaceship - Part 2 - Texturing with MARI
In this section of the tutorial, we'll be looking at how to texture a sci-fi airship model using MARI.
Step 01: Overview of the MARI workspace
Before we begin, here's a brief overview of the MARI workspace. You can click between the 3D painting view under the Ortho tab, and flat UV mode under UV tab depending on the need. If you cannot remember a button function, just let your cursor hover over the button for a few seconds and it will reveal its purpose in a small pop-up tab. In the top-left is the save button - remember to save often. Now let's get texturing!
Step 02: Ambient occlusion
After importing the geometry, the first step for texturing our airship is generating ambient occlusion (AO). Select all of the mesh, and under the Objects menu, select Ambient Occlusion. Then under your Procedural tab in the main shader, select Geometry and then Ambient Occlusion.
The AO may have hard edges which can be smoothened using the Blur tool. First right-click on your AO procedural layer, then 'Convert to Paintable' and use the Blur tool to soften any edges that are jagged. Be sure to save your project as you go.
Step 03: Texturing crevices
Now the AO is complete we need to go over the ship with the Brush tool. By pressing the 'K' key, you can access the brush sets. I find the Velvet Touch brush (under Organic Brushes) is good for soft organic build-up. To reduce the brush size, press the 'R' key and left-click, then push up and down or left and right according to the size and fall-off. For the brush opacity, press the 'O' key and left-click, and slide left and right. Use these tools to softly build up darkness in all the crevices on the ship.
Step 04: Specular map
As we go we can create and add to our specular map. Firstly, under the Channel menu, create a new channel with the name 'Specular'.
Open this channel stack and drag it across to the left of the screen. Keeping this open, return to your Diffuse stack and duplicate our painted AO layer, then drag this layer across to the Specular stack. When you click the Specular shader again you will see what's contained within it.
Next, to increase the specular difference between objects, create a layer within the Specular stack, fill the entire surface with black and reduce the layer opacity to 50%. Next we need to create a mask stack to this layer.
By painting on this layer with black or white paint, we can remove or add the black layer. Think of it as "the lighter it is, the more specular it is."
Step 05: Texturing bronze parts
Now let's bring some color into this ship. I have supplied all the textures used in this project in the downloads. Import the Bronze 2k texture with the image manager. Select individual components, create a new layer in our Diffuse channel and fill in the objects with the bronze texture.
Step 06: Making a rivet texture
For our ship to look as if it's made of large steel plates, using a rivet or bolt texture along the seams will help to give the impression of material type and scale. Firstly, import the blue bold picture provided into Photoshop, and use the Select Color Range tool to select the blue parts. You can adjust the fuzziness to leave only the shadows from the bolts. Then right-click, Select Inverse and delete the blue.
Next we can desaturate the color and place a small gray disc behind where the bolts were to fill them back in. Creating a small gray disc is easily done by making a circular selection and filling it with mid-gray paint. Then export this as a PNG to retain the transparency.
Step 07: Placing the rivet texture
Before we place the rivet texture created in Photoshop, we first need to apply the base metal texture. Import the ‘Plain Metal' texture provided into the image manager, and on a new layer, use it to texture the main body of the ship. When this is complete, make another new layer and apply the rivet texture in such a way to create the effect of panels where you feel they fit best. You can adjust the size of a texture in the buffer window by holding Shift+Ctrl and left-clicking while dragging left to right. You can also change the color or tone of the texture being painted by changing the color in the swatch in the top menu.
Step 08: Additional metals
To create a variation of metal types, I think we should apply a lighter type of metal to the sides and front of the body, as well as more bronze on some of the smaller details. We can achieve this using the plain metal material again, making another layer, then adding an adjustment stack to that layer and selecting HSV. When you select HSV a new window will open and you can use the V slider to brighten the value of the metal.
Step 09: Detailing some more welds and bolts
To break up the plain areas a bit, and add some more detail to the ship in general, we can start to add some more bolt textures to the front of the ship and the fin. We can also start to apply some welded textures using the 'weld' texture provided. Make sure to apply these textures on separate layers so that we can blend them later if it is necessary to, or use them for some specular masking.
Step 10: Texturing the engine
Now we need to start filling in some of these white parts on the engine. I've supplied a texture called 'old polished metal' in the texture downloads to use on the main part of the engine and for the propeller strut. For the piping we can apply the copper texture supplied. By applying textures in separate layers and using an adjustment stack we can tune the lightness or hue of metals to slightly differentiate them if desired.
Step 11: Updating the specular map
Using the textures we have already painted from the diffuse channel, we can now duplicate them and drag them across into the specular channel stack. Then we need to apply an adjustment stack and desaturate the color, then depending on what the material is we can change its opacity to be darker or lighter in the specular channel. By using an adjustment stack on each layer, we can darken or lighten parts using the HSV value slider. Remember: the whiter, the shinier.
Step 12: Painting the windows
Using the provided texture 'dull window', we can now start to fill in those windows. After importing the texture using the image manager we can fill in the window panes. If the texture looks a bit too dull or dark, we can boost the lightness by using an adjustment stack on the layer with the window texture.
Step 13: Wooden texturing
In keeping with the vintage theme and in the interest of variety of texture and materials, we can paint a nice section of wood paneling on the nose section. Using the wood texture, first paint the front's side panels, before moving or baking the texture. Select the Spline Warper tool on the top and drag a rectangle around the shape. Using the frame that appears, drag the texture to fit the general shape of the nose by pushing and pulling on the frame edges. Then hit 'B' to bake the texture in place.
Step 14: The propeller and side engine
Using the texture 'round metal', we can paint the propellers now. As this texture is very brown, I will use an adjustment stack to desaturate it to be almost gray, and darken it just a little as well. Next, for the side engine section, we can paint the inside of it using the 'mesh' texture. At this point we may fill in the rest of the side engine using the 'plain metal' texture. We can update our specular map with these textures as before.
Step 15: Adding dirt and grime
As a finishing touch it's always good to add some wear and tear to a vehicle like this. First make a new layer using the grime textures provided, and go around the ship and paint the leak stains and dirt build-up in places where you would expect to find it. The key to this is not to overdo the dirt unless that is the look you are going for.
Step 16: Adding dirt to the specular channel
Before merging our diffuse textures we must first duplicate and drag our dirt and grime textures into the specular channel. We want these textures to be dull and non-reflective, so we must apply an adjustment stack and by using the HSV adjustment we can reduce the value until the grime texture is almost black. At this point it's safe to select all of the layers and export them to your desktop. I would recommend renaming them.
Step 17: Making normal maps
We can make our normal maps by using the diffuse textures. First we need to create a new channel for the normal map, then duplicate the diffuse textures and drag them into the normal channel. As the diffuse textures are all separate, we will need to select them all and merge them into one. Then by adding an adjustment stack and selecting 'Height to Normal', we can right-click and export this layer to the desktop and rename it accordingly. Now the texturing is done and the model is ready for rendering.