亲爱的学霸们 这是由Károly Zsolnai-Fehér带来的两分钟论文
Dear Fellow Scholars, this is Two Minute Papers with Károly Zsolnai-Fehér.
Today we’re going to talk about explosions.
To be more precise, imagine that we already have the physics simulation data for an explosion
on our computer, but we would like to visualize it on our screen.
This requires a light simulation program that is able to create an image of this virtual
scene that looks exactly the same as it would in reality.
We have had plenty of earlier episodes on light transport, and as you know all too well,
it is one of my favorite topics.
I just can’t get enough of it.
I’ve put a link to these related episodes in the video description.
If we wish to render a huge smoke plume, we perform something that computer graphics people
call volumetric light transport.
This means that a ray of light doesn’t necessarily bounce off of the surface of materials, but
it can penetrate their surfaces and scatter around inside of them.
A technique that can deal with this is called volumetric path tracing, and if we wish to
如果我们用该技术创造一幅爆炸的图像 那么 最好打包点快餐带着
create an image of an explosion using that, well, better pack some fast food because it
is likely going to take several hours.
The explosion in this image took 13 hours and it is still not rendered perfectly.
But this technique is able to solve this problem in 20 minutes, which is almost 40 times quicker.
The key idea is that this super complicated volumetric explosion data can be reimagined
as a large batch of point light sources.
If we solve this light transport problem between these point light sources, we get a solution
that is remarkably similar to the original solution with path tracing, however, solving
this new representation is much simpler.
But that’s only the first step.
If we have a bunch of light sources, we can create a grid structure around them, and in
these gridpoints, we can compute shadows and illumination in a highly efficient manner.
What’s more, we can create multiple of these grid representations.
它们的工作都是基于相同的数据 但它们有的更精细 有的显然
They all work on the very same data, but some of them are finer, and some of them are significantly
sparser, more coarse.
Another smart observation here is that even though sharp, high-frequency illumination
details need to be computed on this fine grid, which takes quite a bit of computation time,
it is sufficient to solve the coarse, low-frequency details on one of these sparser grids.
从地面实况方案来看 结果是难以区分的 但总体计算
The results look indistinguishable from the ground truth solutions, but the overall computation
time is significantly reduced.
The paper contains detailed comparisons against other techniques as well.
Most of these scenes are rendered using hundreds of thousands of these point light sources,
and as you can see, the results are unbelievable.
If you would like to learn even more about light transport, I am holding a Master-level
course on this at the Vienna University of Technology in Austria.
I thought that the teachings should not only be available for those 30 people who sit in
the room, who can afford a university education.
It should be available for everyone.
So, we made the entirety of the lecture available for everyone, free of charge, and I am so
glad to see that thousands of people have watched it, and to this day I get many messages
that they enjoyed it and now they see the world differently.
It was recorded live with the students in the room, and it doesn’t have the audio quality
of Two Minute Papers.
但是 它做得很好的地方 就在于它提升了这些讲座的氛围
However, what it does well, is it conjures up the atmosphere of these lectures and you
can almost feel like one of the students sitting there.
如果你有兴趣 看一看 链接在视频描述中可用！
If you’re interested, have a look, the link is available in the video description!
而且 请务必阅读这篇论文 它是难以置信的
And make sure to read this paper too, it’s incredible.
Thanks for watching and for your generous support, and I’ll see you next time!
亲爱的学霸们 这是由Károly Zsolnai-Fehér带来的两分钟论文