[Week 4&5] Full Screen Effects, Global Illumination and Colour Processing

Hello!

This blog is covering two weeks ago (week 4) as well as last weeks (week 5) lectures/tutorials. I will cover this weeks (week 6) in my next blog post.
In the past two weeks we were lectured on Full Screen Effects, Global Illumination, as well as shown how to implement Lighting and Colour Processing in the tutorial.

Full Screen Effects(Post Processing)!
This lecture we had was really interesting, learning about how the different post processing effect are created. We were taught on the basic imaging processing effects, such as blurring, HDR/bloom, depth of field and more.
We first went over the different methods of blurring, such as using Box Filtering and Gaussian Bluring. Gaussian Bluring stood out to me because I have used it in Photoshop in the past, and it was interesting learning on how the effect is created.
Creating the HDR and Bloom effect was also interesting. It was shown that it can be done by combining multiple exposures into a single image and blending and using a tone map with it.
An example that we were shown in class, was of batman poster. After using the down sampling effect which gives it a blur, as well as an BrightPass Filter which extracts the highlights, it came out with a really cool looking effect.

Left: Original      Right: Down Sampling + BrightPass Filter

Global Illumination!
In class we also covered Global Illumination and how it differs from direct lighting. We were shown previously the math behind direct lighting ...

... as well as how it is used. This equation is used for calculating direct lighting, which equates to the total amount of light of wavelength λ directed outwards along the direction of w at time t from a specific position x.
Then continuing onto Global Illumination, we learned about radiosity, explained how it is both a unit of light and an algorithm. When using radiosity, it is a way to do indirect illumination/diffuse reflections, as opposed to direct lighting, which uses ray tracing, which also makes use of specular reflections. Using radiosity, it can create effects that are seen in current games, such as Mirrors Edge.

Screenshot from Mirrors Edge

Tutorials!
In weeks 4 and 5 tutorials, we covered different types of lighting, such as Lambert and Phong, as well covering different colour processing, such as rgb/hsl invert, selective colour, grey scale, sepia tone, as well as Dans "psycho pearl" which he created.

Two Shader Examples

Homework!
As for homework, I am still working on my personal standalone framework for the homework question, and I am planning on having question 2 and possibly another finished for next tutorial.
Next week is reading week, so I will have more time to catch up on readings, as well as I will be covering Shadow Mapping and more on cel shading in my next blog.

- Jonathan S.