Terragen 2 - Possibly Use Point Cloud Rendering?

[leafspring]

That's why you don't see outdoor examples, because it doesn't really apply to it.

Why wouldn't it? Color bleeding is basically color(and light) propagation via reflection. If you have a huge blue sky, objects in the scene reflect this blue light and it gets scattered further on to other objects.
An even better example are huge icy/snowy landscapes where bright sun light hits the surface and get's reflected up again onto the underside of the clouds.

[Tangled-Universe]

Why wouldn't it? Color bleeding is basically color(and light) propagation via reflection. If you have a huge blue sky, objects in the scene reflect this blue light and it gets scattered further on to other objects.
An even better example are huge icy/snowy landscapes where bright sun light hits the surface and get's reflected up again onto the underside of the clouds.

You didn't understand what I meant, or I did not say it clear enough.

I will simply quote myself again:

The problem discussed in the article is that GI is barely used because it is too slow and that fill lighting setups are used to simulate color-bleeding and to obtain acceptable render time. I can imagine that the sky could give problems. However, the point of this article is that color-bleeding, a GI feature, is much faster and almost as accurate if not better when using point cloud rendering. That's why you don't see outdoor examples, because it doesn't really apply to it.


With "apply to it" I mean apply to the examples and proof of principles the article tries to show.

[leafspring]

With "apply to it" I mean apply to the examples and proof of principles the article tries to show.

Well, I guess I got that one wrong then.

[Matt]

In my opinion this is something which should definitly be looked into. 4 to 10x times faster, hard to ignore you'd say. Even if implementation in TG2 results in 2-3x reduction it is still a very interesting option.

That's 4 to 10x faster than a purely ray traced GI solution. In Terragen the GI is never purely ray traced, at least not in current builds. A GI light cache is used instead, where most of the GI computation time is spent in the pre-pass. While this isn't the same as point cloud GI rendering, the speed increase is on the same order of magnitude at least, depending on your GI settings of course. There are advantages and disadvantages to any GI optimisation, but as is mentioned in the article, no single solution is a silver bullet.

Matt

[sjefen]

How about GPU rendering? Is that something we could maybe see in the future of Terragen?

- Terje

[rcallicotte]

Matt, thanks.  Could you look at their code to see what we could take from it to do better?  Oh, errr, this isn't Open Source, is it?  Rats.   

[Oshyan]

Matt's response tells me he's aware of the technique, as I would expect, and that he's already come up with his own clever approach that has similar goals (and may achieve similar speedups over a more traditional approach, particularly for our unique scene types). Which is to say I don't think this technique is likely very useful to TG2, based on his answer.

As for GPU rendering, it's certainly something we are looking closely at. The biggest concern right now is the fragmentation in the market. Nvidia has the edge on the actual software and development environment implementation, but ATI has the superior price/performance for current hardware. As far as market share I think it's split somewhat evenly for newer cards. DX10/11 and OpenGL 4 class cards are finally starting to bring convergence and a common set of features for GPGPU work, so I expect the cross-platform OpenCL option to mature faster now. Once OpenCL is in a better state and there is more widespread installation of DX 10/11 and/or OGL 4 cards, it will be a lot more appealing to do GPU accelerated rendering. In the meantime there are other CPU-oriented optimizations we still can make.

- Oshyan