Category: Nuke

Clean up is a very interesting and important content in synthesis. If we need to erase some elements in the material without destroying the picture, we can use the rotopaint node to erase. Then we need to add a roto node to follow the motion of the picture, and a framehold node to change the pictures of all frames to the erased pictures. Furthermore, because the picture has a perspective angle. If we want the material to follow the motion at different angles of the screen, we need to track the position with the tracking node first,  then export the information of Cornerpin 2D. Here is a note: the form of Cornerpin 2D should be consistent with the size of the screen.

In this week’s lesson, we learned how to use CornerPin 2D. The CornerPin 2D node can be used to replace a picture somewhere in the motion picture. The purpose is to map the four corners of an image sequence to or from a position derived from tracking data. In fact, this node allows you to replace any four corner feature with another image sequence. For example, you can use it to place images on a TV screen. For the picture to be replaced in the picture, the Tracker node can be used to generate four tracks on the features to be replaced, one for each corner. Then export the information of the tracking node to CornerPin 2D and connect it to the replaced material.

This week’s focus is on point tracking in Nuke. Tracing means tracking a group of pixels frame by frame and collecting their positions on each frame. Tracker can measure how much motion occurs between frames. We can use this mobile information to cancel the move (called stability) or transfer the move to another element, called matching move, by canceling it. Tracking points are two-dimensional position data. By tracking the correct number of points, we can create the correct movement type in Nuke, and use the Tracker node to adjust – whether it is stable or matching the movement. If we need to replace some content in the material with other materials, this function can solve this problem.

This week’s theme is color modulation.   We can use colorcorrect and Grade to adjust the tone of the material.   When we synthesize the material in nuke, we need to adjust according to the original color of the material, such as saturation, color temperature and gray level.   At the same time, we need to pay attention to how to make the composition of the material be more natural by mixing color.

This week, we continued to review roto. We still need more practice, especially when it comes to actual details. For the picture with only slight tremors, we can first track and match, and then copy the track information to roto’s transform. When we do the project for the balloon festival, this method can help us figure out the big mountains in front of the materials.

The Alpha channel is a special layer for recording transparency information, which refers to the transparency and semi-transparency of an image. Alpha is very important for processing material in nuke. We need to find the Alpha information of the materials and then adjust the color of the materials.

The topic of this week’s lesson is roto. Roto is the basic skill for learning nuke. When we get the material we don’t want to jump right in and do it, look at it multiple times, analyze it. Analyze the places that need roto, which can be divided into several large areas for separate operations, and which places can be solved by other methods. First arrange the general direction, don’t worry about small actions. Then, look at the action nodes of the region to be roto. roto will shake, and crucially, because your roto will keep changing positions erratically as it draws. So if you want it to be relatively stable, it’s best to draw the next key frame with as little change of position as possible based on the position of the point in the previous key frame. In addition, the general motion of large material, in fact, shaking is also good. Because the range of motion is large, it means that the movement is gone. Therefore, the small motion should be solved first. This part is also generally easier to roto. Then you can divide the areas with a large range of motion into blocks. For example, when you raise your hand, you can quickly make a fist with your fingers. Then the parts with a large range of motion can be drawn separately, which is a more efficient way. It is to set the general direction first, and then fill in the small details.

The topic of this week’s homework is the London. We need to make a video to show what London is in our mind.

Because I got Covid-19 last week, I didn’t have a chance to go outside until this Monday. So the video I shot was my first exposure to the outside world after seven days. It made me dell both familiar and strange. There were many fallen leaves on the road. I really like the sound of stepping on fallen leaves. I feel nature from it.

This week’s home work is taking some photos about time. I think time is what I am experiencing, seeing, hearing right now.

P1: Last Thursday was my best friend’s 25th birthday, and we celebrated this meaningful moment together. Birthdays are the most important time of the year for everyone. Candles and cakes can express this meaningful time.

P2: I photographed the plane in Elephant Castle. Typically, planes from China fly over the Elephant Castle. It represents the moment when we are about to begin our study abroad.

P3: I found the national COVID memorial wall by the River Thames. People can put the names of people who have died from COVID-19. This wall expresses very sad time.

P4: This is a stone column by the River Thames. The trace on the stone column is the time, which can remind people of what happened here in the past.

P5: The shadow of the London Eye on the river is very much like a clock. The spin of the London Eye is like the passage of time.

P6: This is the emergency button on the London Eye. Because I have a fear of heights, I was very nervous when the London Eye had a problem and had to restart in mid-air. I couldn’t see the view, just this emergency button. It expresses my inner anxiety and fear of time.