Computer Graphics


  • Saturday, July 26, 2008 - 12:54

    Nothing new, just a high-res picture.

  • Monday, July 21, 2008 - 19:50

    So far our reflections only work on surfaces made of materials that are perfectly smooth. In the real world not all surfaces are pefectly smooth yet are still reflective. So to simulat this for doing refletions we cast multiple rays out from the reflection point to caclulate the direction they are cast we take the normal of the surface at the hitpoint and purterb it using a random gaussian variable. The roughness/smoothness is the standard deviation of the gaussian distribution used for perturbing the normals. So the larger the standard deviation the rougher the surface appears.

  • Friday, July 18, 2008 - 22:49

    Photon mapping is a way to do illumination in 3D graphics. This is my computer graphics project from college.

  • Friday, July 18, 2008 - 09:36

    CaptionThis has been an incredibly annoying project. Granted it stems from the fact that I didn't have all the resources I needed as far as the minute detials behind programming the ray tracer.

  • Friday, July 18, 2008 - 06:59

    A bit out of order, but this post will deal with my work on using quads for area lights. Okay, here's the deal, how do you pick a random point from the interior of a quadrilateral and ensure that the distribution is as uniform as possible? Good question ehh? My math prof thinks so too. We discussed several methods. We are doing this because we need to emit photons from the surface of the light.

    The following pictures of distributions are plotted with 2500 points.

    Method A: Corners Method

    Its easy to select a point inside the parallelogram defined by a triangle, so divide the quad into four triangles, pick a point inside each corresponding parallelogram and average them together. Nice and simple, but it creates a distribution that is obviously not uniform, it shows a strong bias for the center of the quad. To be fair, this was of my own invention. (The red, green, yellow, and cyan dots are from the four triangles, the blue are the actually points.)
     

     

     

  • Friday, July 18, 2008 - 06:57

    Okay, really quick, photon mapping is where we cast photons from the light out into the scene we are drawing and store their interactions with the geometry in a photon map. Then we to a raytrace on the scene, but when we do our lighting calculations we use the information in the photon map as well as direct illumination. This gives us indirect illumination, and with the addition of a second photon map we can do good, cheap caustics. For more info check wikipedia.

  • Sunday, February 3, 2008 - 00:55

    A ray tracing project from my computer graphics class. We built our own ray tracers from the ground up, its pretty cool!

  • Saturday, February 3, 2007 - 12:23

    So far all of our objects are dull and flat, we could easily make this more cool by adding in reflections. The technique is simple, we cast the ray from the eye, hit the object, and then cast another ray reflected off the object. This creates nice reflective objects, the first one only allows things to reflect once.

  • Saturday, February 3, 2007 - 11:48

    What are Jaggies

  • Saturday, February 3, 2007 - 11:45

    So far so good, things are looking pretty spiffy. But there is still something lacking as far as lighting goes. Any ideas? There are no shadows! This must be fixed, we mush have shadows. So how do we do shadows? We cast a ray into the scene, it hits an object and from that hit point we cast another ray to all the lights in a scene. So for shadows we just add one more step, when we cast a ray from the hit point to all the lights in the scene we check to see if anything is between the hit point and the light.