
Hi there, my name is Oleksiy Golovchenko and I am a Freelance Concept Artist and Matte Painting / Environments Supervisor. In this article you will learn how to do a seasonal conversion on an Image.
Doing seasonal changes in modern feature films is very common although it's not utilized through the matte painting technique as much as it used to be. One reason for this is due to modern films having complex camera moves. They need to to have animated vegetation, good support of PBR (physically based rendering) materials and shaders to imitate the look of snow covered surfaces so it keeps consistency in the look of added elements.
This is why, due to tighter budgets, it is still fairly common in episodic tv and streaming content for a matte painter to be tasked with seasonal change work. In other words, the main reason to do it in the matte painting pipeline is cut the cost down while filming on location. In many locations, Summer or Fall weather is easier to predict and the days are usually longer as well as there being no need to keep the actors warm. The consistency of the project might also require footage of different seasons of the same location but due to short filming schedule the studio owns only summer or spring footage of the location.
Two Conversion Tasks
It’s important to understand the difference between changing the Season of the location versus extending the winter set. Here is an example:
The image below is a frame from Game of Thrones the TV series and features a set extension of the winter landscape and not a season change per se. On set background elements were replaced and plate photography was used as a reference for light and scale.

The next image below, however, is a common example of the season change through the DMP approach. The key difference here is that in the first example, you are adding to the wintry look and are allowed to change the background, whereas in the 2nd example you have to keep the overall plate and add snow, weathering, and other elements to transform the season.

Technique
Here are some basic steps you would most likely need to do in order to transform your summer, spring or fall image into a winter scenario.
If you are working in the studio pipeline then most likely your plate would be already neutralized and the overall image temperature will be close to a winter atmosphere. You can do this part yourself roughly with the Photoshop Camera Raw filter (Filter -> Camera Raw) and adjust the color temperature and other values to make it look colder and more wintry.
Note: in a studio production, the final COMP will be further graded by the studio to get the final feel and the look that the Director or Producer had in mind.
Step 1
Assess the plate and decide what parts need to be replaced and what parts need to be transformed/overpainted. If it’s Summer, Spring or early Fall you most likely need to remove or change the greenery of some elements. If it is late Fall then you might keep the majority of the trees as they are most likely to be leafless at this point.
Note: Evergreen trees in the Winter scenario will keep their leaves but will accumulate the snow on them.

Step 2
Clean up the Plate of unwanted greenery and separate the elements of the scene if needed so you can put some snow behind the lamp posts or railings, for instance. In this example, the final shot had a bit of a dolly move so it was necessary to have some elements separated.

I left the bushes on the bottom left screen as they might stay green all year long and possibly will just accumulate the snow on top of the branches. I replaced the yellow tree on the screen left with leafless branches to keep the consistency of the elements.
If you can, try to find the photos of the location in the Winter time to understand how much snow you can expect etc. It doesn't have to be the exact angle or time of the day, you just need an overall reference to guide you through.
Step 3
Start adding extracted snowbanks to the ground and all the elements that will accumulate snow in Winter.

Don't paint all the snow by hand by sampling the colors from the photos. Use photo elements as much as possible in order to achieve a photorealistic look. Snow is a very tricky subject in terms of light interaction, accumulation of pattern and overall shape. Usually I paint only small parts where it will be almost unnoticeable.
Step 4
When you are finished with big shapes and main elements it’s time to add smaller elements to the scene to sell the Winter weather even more.

I added snow accumulation on the walls and roof shingles. This might look like a long and tedious process but there is a quick approach to it!
Duplicate your clean plate layer (Ctrl+J), invert it (Ctrl+I), desaturate it (Ctlr+Shift+U) and apply Levels Adjustment to it as you see below.

Now go to the Channels Tab and make a copy of any Channel; we need to use this as a mask for the weathered snow. Create a new layer and paint in the area with snow with an irregular brush to have a nice texture on the walls or rooftops.
Pro Tip: Avoid using the Black and White layer in Add or Screen mode because you won’t be able to export it separately from your clean plate if needed.

Now apply copied channel as a mask and paint out some areas if need to add an extra irregularity. Here is how all the added snow elements look like on isolated background:

In general this technique requires following these steps:
- Plate clean up and separation of elements.
- Replacement of trees or adding the snow on existing greenery in order to create consistency of the elements on location.
- Extraction of snow elements from reference photos in similar light scenarios. Also watch out for perspective on the elements like icicles and snow banks.
- Color correction of the new elements.
- Detail extraction from the Plate in order to emulate accumulation of snow on the broad and flat surfaces like brick walls and rooftop shingles.
I hope you have learnt from this Tutorial! To learn more check out these more in depth tutorials on this subject:
- (Coming Soon) Summer to Winter conversion, MattePaint Academy
- Matte Painting - Digital Matte Painting Tutorials (3d Total)
- d'Artiste Matte Painting Book 1 - Chapter “Golden Gate” from Chris Stoski
Thanks for reading, if you would like to see more of my work or connect with me, follow me here:
~ Oleksiy Golovchenko