Rendering a spacecraft scene - Part 3 of 3
In this, the last article of the series, we're going to cover creating an environment for our ship, and modeling a hangar with simple elements. Then we'll set up the final render in Marmoset Toolbag 2, adding secondary sky lights on the HDR to obtain nice specular reflections on the ship and interesting shadows on the floor, as well as adding fog and depth of field to make a more realistic scene. Finally we'll cover every layering step in Photoshop for the post-production of the final image, from the addition of dust, smoke and other effects, to the final adjustments in terms of contrast and color balance to give more drama to the image.
Step 01: Modeling the environment
For the final image I need to create an environment for the ship. In the original concept, the ship was located in a space hangar. Inside 3ds Max, I model every single object that composes the hangar: the floor, wall, roof, tubes, cables, metal structures and so on. I place a camera and start to build the scene as similarly as possible as the concept. I use very simple meshes for the elements of the environment. Most of them will be very blurred in the final image due to the camera's depth of field, so I don't make any detail on them, only adding little chamfers on the borders. Keep in mind that the ship is very big, so be careful with the proportions of the elements. Focus on the elements you can see in the image; it's not necessary to model a complete hangar as long as the final image looks correct and good. I don't make any UVs for these elements - I only apply a UV map modifier.
Step 02: Scene setup in Marmoset Toolbag 2
Inside 3ds Max, I organize all the elements in different layers and export them in groups; for example, all the element of the wall, the elements of the floor, all the tubes, cables, and so on. This way it's going to be easy to manipulate them in Marmoset Toolbag 2.
I import all the OBJ files into Marmoset Toolbag 2 and start to create different materials for them. I don't use any textures, only playing with the glossiness, albedo and metallic values for each material. I only used a simple concrete map for the wall and floor materials. Notice that I don't add too much reflection to the materials because I want to be faithful to the style of the concept and keep all the elements dark.
After this, I start to play with different HDRIs, choosing 'Castle Sunset'. I also set up the camera with a 33mm focal length and add a flare effect.
Step 03: Adding secondary lights
Once I have the scene with the selected HDRI and all the materials applied to each element, I start to add more sky lights around specific areas to obtain nice shadows on the floor, visual interest points and the main focus on the middle-back area of the ship. Before starting to add the lights, I check the 'Local reflections' and 'Ambient occlusion' options under the Render tab.
In the image you can see each light I create, adding them one by one (I've marked them with a green arrow) so you can see the progress in the illumination. When you add a sky light into the Light Editor, it automatically assigns a color to that light depending on its position on the HDR map. I didn't change any colors, but kept all the lights with their default color. After this I also add a subtle bloom effect.
Step 04: Adding depth of field and fog
With all the illumination done, it's time to activate the depth of field to give the image a more realistic feeling. I play a bit with the near blur, far blur and bokeh size, trying to find a balance where nothing looks too blurred, with a nice and smooth transition from the focal point (the ship) to the very back.
At this point the image looks quite good but it's missing some atmosphere, so I add a fog effect. The fog is very useful to separate the elements in the foreground and background, and again it gives a very realistic feeling to the scene.
Step 05: Layering different exposures
At this point I've finished the scene's 3D stage, so let's go to Photoshop to post-produce the final image. I use Marmoset Toolbag 2 to render out three images at different exposures: 1, 2 and 0.3.
The base image in Photoshop is the one at exposure 1. This image has very flat colors, with everything looking too homogeneous; I want to add some more contrast and a more dramatic feeling to it, and to do so I use the image at exposure 2 (at around 30% Color Dodge blending mode) to mask the lightest of the areas; and the image at exposure 0.3 (in Soft Light blending mode) to mask the darkest of areas. Using this technique here, I can therefore start creating some Vignette effects but with the real illumination of the scene.
Step 06: Adding dust particles
I search over the internet for dust particle images and test a few of them. I finally choose one with very small particles, remembering to always be consistent with the proportions of the elements, even with the dust. The inside of the hangar is a huge place and the small dust particles will help to create that sensation. I use the image in 60% Color Dodge blending mode.
Step 07: Adding smoke
For the smoke I use an image from textures.com.
In Photoshop I select the white areas of the smoke with Color Range to get rid of the blue background. I make several duplications of it and put them around the image, always rotating and flipping them to avoid any evident repetitions, and masking some regions to hide or show different areas of the smoke.
I usually use them in Pin Light blending mode at low opacity, but this depends on the result you want to achieve. Previously in Marmoset Toolbag 2, I rendered an image with a transparent background to use as a mask for the smoke, turning off all the elements except the ones in the foreground (ship, tubes, cables, and so on.).
I use this image to create a mask in the smoke folder, so these elements will be in front of the smoke. You can always manually paint out any areas of the mask as you wish, to bring the smoke to the front or back.
Step 08: Lens flare effect
I always like to add some lens flare effects in the shiniest areas of the image, to give a really nice sci-fi look.
Be careful to not add too many, otherwise they will look too redundant. Just choose some areas to place them as a final detail in the image - usually one or two is enough. This time I choose a lens flare image from the psdbox and use it in Screen blending mode; one in the main cabin to help the focal point and the second in one of the roof lights. Another detail I add to the image is some small dots with a simple brush to suggest some lights; again, two or three is more than enough here.
Step 09: Adding texture to the wall
The wall on the left looks too flat, so I add a texture to it to make it look better. This time I use an image from 'Total Textures V07:R2 - Sci-fi'. First of all I play with the arrows of the blending options inside the Layer Style window. This way I remove some of the lightest areas of the image. I apply the image in Overlay blending mode and make a duplication set to 50% Multiply to intensify it a bit. I also paint a mask over the region of the wall, and finally I add a small decal in the corner of the wall.
Step 10: Adjusting Curves and Levels
The final step to complete the post-production is to add even more contrast and drama to the image. To do so, I make some adjustments to the Curves, Levels and Color Balance.
Once you've finished all your adjustments, you can make a copy of the merged image and add a bit of Sharpen filter (at around 30-40%) to make it look more defined. At this point we can say the image is done!
Top tip: The Sharpen filter and Smudge brush
At the end of the composition, applying a Sharpen filter to the image will make it look clearer. Don't use it at 100% or it will look extremely sharp (I usually use it at 30%-40%). Once you've applied the Sharpen filter, you may encounter some specific high-contrast areas that have unwanted jagged lines. This inconvenience is very easy to fix - just use the Smudge brush in a very small size and pass it in one direction to smooth over the jagged edges and the neck.