It's interesting to see how the use of alpha not only allows the creation of complex geometries, but also the appearance of realistic, translucent leaves.
lilliput
Would the texture be animated to create fluttering leaves? Also how are the shadows created (and animated) if the underlying geometry has minimal complexity?
maq
Can someone explain how alpha is used in examples like this for creating geometries? Did not quite catch the relation in lecture
tulum
Does it mean to use the alpha channel to create transparent leaves or the standalone tree?
ecohen2
@maq I am not fully certain but I think it has to do with making pixels more transparent around the leaves if they're not in the leaves so it looks more realistic
Kent
Here is an interesting paper on rendering complex foliage with a lot of leaves: https://www.cs.ucsb.edu/~holl/pubs/Candussi-2005-EG.pdf
The main challenge in rendering trees is finding a surface representation of the tree that has manageable geometric complexity while at the same time maintaining high realism at various distances. Rendering each leaf as a collection of triangles is prohibitively expensive, however according to the authors of the paper most approaches to rendering trees have simplified them too much. As a result, the authors describe a technique for clustering leaves and branches that looks realistic and manages to maintain low geometric complexity. I recommend giving it a read if you're curious (they also implement various shadow and animation techniques for rendering trees).
It's interesting to see how the use of alpha not only allows the creation of complex geometries, but also the appearance of realistic, translucent leaves.
Would the texture be animated to create fluttering leaves? Also how are the shadows created (and animated) if the underlying geometry has minimal complexity?
Can someone explain how alpha is used in examples like this for creating geometries? Did not quite catch the relation in lecture
Does it mean to use the alpha channel to create
transparentleaves or the standalone tree?@maq I am not fully certain but I think it has to do with making pixels more transparent around the leaves if they're not in the leaves so it looks more realistic
Here is an interesting paper on rendering complex foliage with a lot of leaves: https://www.cs.ucsb.edu/~holl/pubs/Candussi-2005-EG.pdf
The main challenge in rendering trees is finding a surface representation of the tree that has manageable geometric complexity while at the same time maintaining high realism at various distances. Rendering each leaf as a collection of triangles is prohibitively expensive, however according to the authors of the paper most approaches to rendering trees have simplified them too much. As a result, the authors describe a technique for clustering leaves and branches that looks realistic and manages to maintain low geometric complexity. I recommend giving it a read if you're curious (they also implement various shadow and animation techniques for rendering trees).