Thursday, 25 February 2016

Graphics Work

A quick update on what I've been working on recently.

For one of my modules Simulations and 3D Graphics, we were set a task to learn lighting and materials. So far I have implemented a single light, using ADS and blinn-phong (again).


The camera can rotate, move forward/backward. The armadillo can be rotated on it's pedestal and the whole scene can be rotated.

Sunday, 7 February 2016

Project 5: Stanford dragon rendering



This dragon is one of the many models which the Stanford University Computer Graphics Laboratory scanned. More info http://graphics.stanford.edu/data/3Dscanrep/. I used this to practice for an upcoming module, it is made in OpenTK and uses OpenGL 4.5.
 
Work for this included:
  • Loading vertex and normal data from .OBJ.
  • Parsing material file for Blinn-Phong attributes.
  • Blinn-Phong glsl shaders.
  • Setting model/view/projection matrices.
  • Configuring camera and light positions.

Tuesday, 2 February 2016

Project 4: Ray casting with a 2d graphics library.


Implementing this using one of my favorite frameworks (https://love2d.org/) in Lua was a lot of fun!

This is heavily inspired by Wolfenstein 3D.

It involved simple trigonometry, calculating ray/shape intersections, figuring out how to map textures and lighting effects.

A problem I encountered was a fisheye lens effect, because for each ray projected into the world, I would map the intersection distance directly to the height a wall (which is a group of line slices). However what I needed to do was calculate the perpendicular distance of the intersection using the projection plane as a reference.

Fish-lens effect


Here's a great image which helped me understand the problem a lot, originally my raycasting method resembled the one of the far right.


Here are the resources I used:
  • http://permadi.com/1996/05/ray-casting-tutorial-table-of-contents/ - Help with the projection plane/intersection distance calculation.
  • https://en.wikipedia.org/wiki/Linear_interpolation - How I map the texture coordinates onto the side of a shape given a set of intersections with it.

The difference between class and object.

 The difference between class and object is subtle and misunderstood frequently. It is important to understand the difference in order to wr...