Temporal Set Inversion for Animated Implicits

Project page with paper pdf and supplemental video can be found here.

Note that this is all research-quality code. The interesting bits are contained entirely within /src/compute.wgsl.

Setup instructions

1. Download and install Rust
2. Clone this repository
3. Run cargo run --release -- --Awarnings in the root directory

Controls

1. Press r to hot-reload /src/compute.wgsl
2. Camera controls are w, a, s, d + mouse to look
3. Scroll up or down to change movement speed
4. If the camera controls feel wrong, disable the scene-dependant view matrix modifications in fn rt_main in /src/compute.wgsl

Shader Parameters

1. Ctrl+f for "PARAMETERS" in /src/compute.wgsl, here you will find the following:
2. localsubdiv controls the octree resolution, e.g., 8 -> (2^8, or 256)^3 and 10 -> (2^10, or 1024)^3
3. delta controls the temporal error tolerance, e.g., 0.01 (depends on the Lipschitz bounds of f)
4. pointsample enables world-space point-sampling within indeterminate leaves
5. fastenabled enables the fast-evaluation optimization
6. lipschitz_corrected enables Lipschitz-correction on delta
7. swept_volume enables swept-volume rendering
8. normalvis sets the surface color to the world-space normals
9. cinematic enables naive pathtracing with totalsamples samples per pixel
10. fast_normals enables per-pixel normals via finite-difference
11. scene selects which scene's normals (if fast_normals is true) / lighting / camera settings to use

Other parameters

1. To enable fullscreen, set shouldbefullscreen in /src/main.rs to true
2. To save frames to disk, set save_frames_to_disk in /src/main.rs to true
3. To save timing data to disk, set save_timing_to_disk in /src/main.rs to true

To switch scenes

1. Make file_contents in /src/IR.rs read from scenes/something_else.ll
2. Set scene in /src/compute.wgsl according to the comment next to it

To add a new scene

1. Create new file /scenes/example.cpp and paste in your GLSL code
2. The field function must be named f, mapping 4 floats x,y,z,t to a single float
3. Paste this at the top of /scenes/example.cpp

   #include <math.h>
   #include <cstring>
   #include "include/swizzle/setup.h"
   #include "overloads.h"
   

4. Install Clang and run ./compile.sh example to generate example.ll
5. Fiddle with the code until example.ll contains no branches or casts in the field function
6. In /src/IR.rs point the constructor's file contents to scenes/example.ll
7. Set scene in /src/compute.wgsl to some new value
8. Make sure fast_normals in /src/compute.wgsl is set to false to get per-voxel normals. If you want per-pixel normals, keep reading

To enable fast per-pixel normals on the new scene

1. Paste your GLSL code into a temp file called example.frag

2. Paste this at the top of example.frag

   layout(location = 0) out vec4 color;
   void main() {
   	color = vec4(0.0);
   }
   

3. Run naga example.frag example.wgsl in the CLI

4. Paste the contents of example.wgsl at the top of /src/compute.wgsl, ignoring the FragmentOutput and color lines (top of the file) as well as fn main() (bottom of file)

5. Rename fn f to something else, e.g., fn example

6. Add a new case to fn finite_diff_normal in /src/compute.wgsl to call fn example if scene is set appropriately

7. Make sure scene in /src/compute.wgsl is set to your new value

8. Set fastenabled in /src/compute.wgsl to true so that fn finite_diff_normals is used

I've tested this code on Windows 10, Vulkan backend, with an RTX 3080 / i7 3930k. It should in theory work on other operating systems / GPUs and even the web thanks to wgpu. If you need help setting it up, please open an issue.