In lecture we went over why the rays are slightly off for reflection - not sure I understood this right, is it because the origin of ray vector is not a single center point but a surface of a cube?
ecohen2
^ That is what I understood from lecture as well @cmate!
Based on the drawing on the white board, it seemed like the rays would not be super far off but I imagine the difference would grow as the object in the center grows.
kencheng
I believe at high level, it works like this:
1) Pick a point in the scene.
2) Store the received color from all directions to the chosen point. (We choose to store this information in a cube map).
3) When you want to get the light of a point on the reflective surface, find the ray of reflection, and use the above to get the light value in the direction of the reflection. Note that the point on the reflective surface IS NOT NECESSARILY the chosen point. Thus, there will be discrepancies.
It is worth noting that the picture above is not showing a reflection. (If you check the Wikipedia article, the article notest that the image only shows the cube map, not a reflective cube).
In lecture we went over why the rays are slightly off for reflection - not sure I understood this right, is it because the origin of ray vector is not a single center point but a surface of a cube?
^ That is what I understood from lecture as well @cmate!
Based on the drawing on the white board, it seemed like the rays would not be super far off but I imagine the difference would grow as the object in the center grows.
I believe at high level, it works like this:
1) Pick a point in the scene. 2) Store the received color from all directions to the chosen point. (We choose to store this information in a cube map). 3) When you want to get the light of a point on the reflective surface, find the ray of reflection, and use the above to get the light value in the direction of the reflection. Note that the point on the reflective surface IS NOT NECESSARILY the chosen point. Thus, there will be discrepancies.
It is worth noting that the picture above is not showing a reflection. (If you check the Wikipedia article, the article notest that the image only shows the cube map, not a reflective cube).