Month: May 2022

This week I finished the third scene in our trailer: the restricted area scene. This is the first version of it and will be adjusted in the next week.

The whole process of making the restricted scene is quite same as the other two scenes. Since we have already find the proper references and finished the storyboard, I can focus more on the layout and lighting of the scene.

I firstly find some references for this scene and try to feel the atmosphere inside of them:

Most of these scenes show the same two features: a little bit of artificial traces and foggy air.

I listed several compotents in this restricted area scene:

• Foreground: Tree stump, wreckage, barbed wire, grass, branches, rocks.
• Mid—scene: Abandoned watch tower, trees, rocks, branches.
• Background: Mountains, trees.

Based on this list, I gathered some assets and made part of props by myself (barbed wire, mountains, rocks). I then layout the whole scene in unreal engine, trying to provide a sense of desolation and stillness in it.

Here is the final result:

Next week I will optimize these three scenes, especially the forest scene. I’ll add more details to the foreground and adjust lights.

Scene Rendering

After adjusting the quality of the destruction and smoke sim, I rendered the scene and composited it in Nuke this week. Then I added some sound effects in it. Here is the final result:

Procedual Saliva HDA

After that I started to make another visual effect, which is a procedual saliva digital asset.

Saliva is an important element of realistic creatures. For example, we can find creepy saliva effects in film Alien (1979) and The Thing (1982), which brings a great sense of realisim and horror.

I firstly find some saliva reference:

As we can see, saliva can be separate into 3 types:

• Filamentous dropping saliva
• Punctual dropping saliva
• Filamentous dangling saliva

Filamentous dropping saliva and punctual dropping saliva can be easily simulated by using high viscosity fluid sim and surface tension. However, filamentous dangling saliva can not be easily achieved by using fluid sim. It is more like a fluid-like cloth simulation. What’s more, the shape of saliva has some regular patterns: both sides of saliva is thick and the middle of it is thin. Such kind of feature shows a sense of high viscosity.

I used a combination of vellum cloth and VDB to sim filamentous dangling saliva. The main idea of it is to build up lines using VEX, and then use vellum solver to sim these lines. After that I turned lines into particles and then turn them into VDB, and finally convert them back to polygons.

This is a procedual method of building saliva. Therefore, I can easily build saliva on different creature models by using the HDA. What’s more, I can change the shape and numbers of saliva by using customed attributes.

I did a simulation to test the result. Most part of it works well. However, a bending can be easily found on the saliva when the the mouth is closing. This can be a problem because it makes the saliva more like a cloth rather than a fluid. I think the problem comes from the vellum simulation. I need to add more elasticity to the sim to prevent this kind of results.

After that I optimized the volume of saliva, here is the result:

A rendering for the saliva:

A movement test for the saliva:

This week I finished the cave scene in project01.

I used Houdini to build up the frame of cave and background mountains first, which can easily control the shape of the cave. After that I sent it to unreal engine to build up other parts of the environment.

I used the same techniques that I have tested in the last scene to build the scene. This time I mostly focus on details and the layout of the scene. Based on the storyboard and refereneces, the cave should be deep enough to show a sense of mystery. What’s more, the scale of the cave should be large enough to show a better composition of the whole shot.

I added three layers of textures on the landscape to make sure there are enough details on the ground. Then I added some branches and small rocks to push the details to another level.

Below is the test shot for the scene. The LOD of the landscape hasn’t been removed successfully. I will figure it out next week.

This week I started to build our scenes. After discussing with Yaozhang, I choose to build the forest scene, cave scene and the restricted area scene.

There are about 6-7 scenes that we need to build for the whole trailer. The forest scene is one of the most important scenes and it is a little bit easier to be approached. Therefore, I made a pre-version of the forest to test the result.

The aspect ratio that we chose is 2.4:1, which can bring a great sense of cinematic to the shots. I gathered some textures and models to build up the scene and lightened the scene by myself. The landscape is made by unreal landscape tools and houdini, and shaded with a blended material. It is still the first version of the scene and the quality can be improved later.

I animated a camera to test the shot. The mp4 smoke sequence works not well at the beginning. I changed the media texture to exr files and solved the problem.

The testing result is fine, which doesn’t take much time to be built and rendered. However, I still think the lighting can be improved and the forest is still not dynamic enough. One of the biggest problem is the size of the file and scene optimization, which are some main issues that I need to fix in next week.

From this week I decide to use destruction and pyro techniques to make a more interesting and technicial shot. The whole shot should be finished in 1 to 2 weeks.

What I want to make is a scene in which a creepy monster/creature breaks through the side wall and running towards the camera. The shot will lasts about 7-10 seconds, which focus on the dynamic effects of buildings and creature and the atmosphere of the whole scene.

I decide to build up a corridor for this shot. I firstly did a research on horror corridors on the internet and gathered some lighting references. After that I started to build the frame of the scene. What I need to do is to build part of the corridor and duplicate it forward to make whole corridor. Each part of the corridor shares same UV and textures.

Since I don’t have enough to focusing on creature modeling and rigging, I searched on the internet and found an alien rigged model, which is pretty nice(I can use it to test some CFX later). The texture of it is not at a high quality (no SSS, and low res), maybe I’ll replace it later.

After that I baked normal textures in substance painter. Then I made other textures by combining quixel scaned textures and baked textures together in substance painter. The uv had some problem at the beginning and was solved then quickly.

I then placed the creature into the scene and render a shot with redshift. The whole atmosphere is quite close to what I want. What I need to do is to add a little bit more details on the ground and ceiling. The next part is to animate the creature (it is an alien model acturally) to make the shot more horrible and set up the wall for destructions. The animation is quite important because it drives the range of whole destruction. It should be powerful enough to make the VFX looks better.

After that I did a rough animation for the creature and set the position of the camera.

I import all the environment and animation to Houdini to make the RBD simulations and pyro sim.

Below is a test for the scene. The smoke sim is fine. However, I think the constraints of each fractured pieces still have some problem. I ‘ll add a hard constraints to test the result later.

Here is a rendered one testing the smoke and other textures:

This week we had the second meeting and finally selected some key shots for our film. Then Zhenzhong finds some music for the film and made a short cut for our shots as a reference for our future works. Most of these shots can be finished in UnrealEngine, and few of them (for example, close-ups) need to be done in Maya and Arnold.

After that we started to make assets. Me and Yaozhang will focusing on the environment of shots, while Zhenzhong and Ziyin will focusing on the character and props.

I decide to to some research on UnrealEngine and find out which techniques that we need in these shots. I will start to layout the environment after I fully prepared the UnrealEngine.

What may covered in our shot is forest layout, terrain layout, texturing, lighting and some simple effect like dust or smoke. I learned how to make fake smoke in Unreal Engine by using exr sequences and customed textures. With the combination of fake smoke and UE build-in height fog, we can easily create the atmosphere that we want.