Category: Advanced & Experimental

This week we were carrying on with the side tasks we were given during the completion of the garage project. I worked on green screen work and the scene of the girl in the snow.

I used the keylight node and then the eyedropper tool to remove the green from the greenscreen. I then merged the origonal scene with the background of the snow.

I then premulted the greenscreen scene which added more detail to the hair strands and set it apart.

I then needed to adjust the levels of colours emmitting on the keylight node, to make sure no details were lost of the girl and her hair during motion.

I feel like this enabled more detail to come through and it less obvious this was made from a green screen.

This week we looked at motion vectors, and more greenscreen work.

We were given homework to remove markers on an actress’ face, these are the markers you see in facial motion detectors for CG characters. To do this, i used the roto paint node which allows you to use clone to remove marks by pasting colours from directly nearby the mark is you want to remove, and painting this colour over it on the scene. I tried to make this as realistic as possible, blending the parts of her skin in and making sure it wasn’t obvious where the markers were.

I then worked on the feedback I had given to me about my garage project. I used the colour correct node to reduce the highlights on my tyre, so it would blend into the realistic CG comp more.

This week I was overlaoded with collabrative unit work, so I had little time to work on more Nuke and Maya work which I acknowledge, and will prioritise catching up on this in the upcoming weeks and over easter.

This week I needed to work on getting my garage project finished with the deadline quick approaching. I first needed to merge all my compartments of my nodes together sucessfully. When I tried doing this, one asset would become transparent. I realised it was a problem with what I was merging to what. Instead I needed to have a chain of merges that gradually introduced new assests to the scene.

I then linked my roto to the scene, and added the CG machine we were given. I added a few more colour correction and grade nodes so that this would blend into the scene more, and luckily my roto worked perfectly with the machine.

I still needed to add the smoke and shadows, but I rendered out my progress so far for my blog now all my assets, roto and machine work in the scene together.

In terms of working out the shadows, I had never done this before. Luckily we went over shadows in class this week. We were given a sphere and cast a point of light in the direction of the geometry for it to cast a shadow in the scene. We could then adjust the intensity of the shadow.

This was great, however my assets in the garage project were 2D. I had imported them as exr files from maya. I thought this would be easier for the camera tracking for me as I wanted to practice the use of cards more as a projection for objects. Luckily, we used the technique also for 2D ‘fake’ shadows which is what I would need to use. We were given the example of a paper figurine, and by simply using the multiply and blur node, with some shape adjustments on a card, we were able to create a fake shadow.

This looks realistic and would be a great method for me to apply to my project.

Work from home

This week I applied my knowledge from what I’ve learnt to finish and render my garage project.

I first added smoke with some guidance I had recieved from my teacher in class. I needed to link the smoke with the roto but invert it so that the smoke would be inside the roto, therefore inside the room. I also needed to increase the multipy slider to increase it’s intensity.

I then took the technique of the fake shadow card and applied it to my tyre and ladders. I added a double shadow for both assets, as the shadow would be hitting the wall and the floor. I made the intensities of these vary however to add realism.

We have been exploring the process of green screen removal, which involves extracting the green background from a video and replacing it with other visuals.

One of the techniques we have covered is the use of the hue correct node, which enables us to remove the green color from our footage by creating a node graph. By selecting the green color in the graph and dragging it down, we were able to effectively remove the green screen from our footage and prepare it for the insertion of other visuals. While this technique may seem relatively straightforward, it can be a powerful tool for creating compelling visual effects.

We also explored the key luminance node, which can be used to selectively affect certain areas of an image or video. This technique involves creating an alpha image and selecting the specific areas that we want to modify.

During our lesson, we experimented with this technique by selecting only the sky in our footage and adjusting the levels at which it was selected. This enabled us to fine-tune the visual effect to create a more natural and realistic result. Overall, the key luminance node is a valuable tool that can be used to create a wide range of compelling visual effects.

We explored how to adjust the lighting in specific areas of an image or footage. During our lesson, we used rotoscoping to isolate the particular area we wanted to modify, and then applied various nodes, including the shuffle, grade and keyer node, to enhance the lighting and make it appear brighter, we used this example of a snowy landscape to make the bottom half more light.

We then looked at creating rays of light coming out from behind objects such as trees. This enhances the lighting apparent behind an object. This was done by using a node called volume rays, along with the selection of just the tree using rotoscoping.

We also learned a basic technique for creating a blurred effect in a specific area of an image using rotoscoping. This technique involves using an image to create a rotoscope of a circular area, and then applying a blur node to that area. Finally, we merged the two to create the look of a blurred circle in the specific area of the image.

Work from home

For the garage project I felt like I needed to add another big asset to the scene.

I decided to add ladders to fit the theme of the project. This also fit in well with my other assets such as the tyre and the mechanical posters. I downloaded a 3D model of four ladders together. I then added the texturing in Maya adjusted the placement of the ladders.

I then rendered these out and added this file to my Nuke garage project script.

I then followed the same method I had used on my other assets and tracked these ladders through the camera tracker, and then synced this up to the scene. Again, I used the axis on the wall I wanted them to stay against and then created a card which I then linked to the original image of the 3D models. These then successfully tracked with the camera and moved with the footage.

I then had to do the homework we were given which was linked to the green screen methods we had been using. I first tried using the hue correction node and the keyer node to adjust the levels of permittance. However, this was picking up on too much green in the image.

I decided to use another method we were shown for this task.

For this I used the Keylight node in which you can select a colour using the eyedropper tool and adjust how much of the levels you want to be removed on the footage of this specific colour. I selected the green on the green screen and adjusted the numbers until it was at a level of green removal that looked professional.