Week 6 - Brutal Legend and Midterm review

We didn't learn anything new this week but we did watch a video about the making of Brutal Legend to show how what we learned is applied in popular games. Our second lecture this week was just a review for our midterm after reading week. 

Overall the video was really interesting to watch and the developers made some really smart choices when developing Brutal Legend. One thing that really surprised me was how they chose to render the sky. They chose to make their sky one giant particle instead of using a traditional sky-box. They also talked a lot about how they did particle rendering and lighting. 

Week 5 - Lighting and Shadow Maps

This week we talked about global illumination and shadow mapping. 

     Global illumination is a general name for a group of algorithms used to give more realistic lighting to a 3D scene. These algorithm's allow objects to be lit not only from light rays directly from the light source but also by rays that have bounced off of other surfaces. As seen in the image above the white surfaces are tinted with colour cause by the light rays that have bounced off of the coloured green and red walls. 

     Ray tracing is a technique that can be used to achieve more realistic lighting in a scene. Ray tracing is basically trying to simulate rays of light. Ray tracing is done by tracing rays of light from a light source and checking to see how it interacts with the objects in the scene and render accordingly.

 

Shadows:

     Shadows are caused by absence of light in an area. In a 3D scene this is usually because there is an object in-between the light source and the object creating an obstruction for the light.

Shadow Maps:

The algorithm for shadow mapping that we went over in class required 2 rendering passes. During the first pass you would render the scene from the light's viewpoint, draw blockers and store nearest z in the z-buffer and the resulting depth buffer is the shadow map. The second pass is done from the observer's viewpoint and you compare the depth of each pixel against the shadow map to determine which pixels are in shadows.

Week 4 - Fullscreen Effects/ PostProcessing

This week we learned about full screen effects and post processing effects like blur and bloom. 

Blur: 

Blurring is done by applying a filter to the texture of your frame where each frame is assigned a weighting. 

In the image above each pixel is equally weighted.

Gaussian blurring is done in a similar way except each source pixel is not equally weighted, pixels are weighted higher in the center. As a result, bigger the window the stronger the blurring.

HDR/Bloom:

HDR and Bloom are post processing effects that are actually quite simple to do, they are done by doing multiple pass-throughs before displaying the final image.

     1. Render 3D scene to offscreen framebuffer
     2. Highlight bright areas(tone-mapping)
     3. Apply a Gaussian blur to highlighted areas
     4. The final image is equal to the blurred frame + the initial 3D scene

Above is an example of HDR and bloom in a video game, in this case it is The Legend of Zelda : Wind Waker HD remake. 

GDW:

We are planning on adding some postprocessing effects into our game and currently we are working on our framework to make these effects easier to implement.