Topic: New in LumenRT: Realtime GI

[Ecuadorian]

Coming soon.

[AnilMundi]

Coming soon.
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Wow, this is absolutely gorgeous! I checked the LuminRt website and the pictures are incredible. Have you tried it? I'm downloading the trial as we speak. Is this what the new lighting in Lumion 3 is going to be like?

[peterm]

Lumion weblog: Lumion 3 Preview: latest news:


"Global illumination preview
 
October 12 2012
 
In Lumion 3.0 a new feature which automatically reflects light as it hits a surface.
 
The effect is viewable in real-time so you can directly see the change as you modify materials or lighting.
 
For example you can have a room with a green floor and it will light up green. Point a light at a red sofa the reflected light will illuminate the room with red light."

[Ecuadorian]

I checked the LuminRt website and the pictures are incredible. Have you tried it?

Yes, I did. Those pictures are of baked GI, not real-time GI. GI baking can take hours in the current version. That's why I haven't bought a license yet.

Is this what the new lighting in Lumion 3 is going to be like?

I also want to know that. That's why I posted the video in the first place. I want to know if Lumion's implementation of real-time GI will be similar to this.

[AnilMundi]

So, I don't understand what you say about LumeinRT. This video you posted says realtime illumination, but you say it takes forever to "bake"? I'm trying it now. I've tried only draft so far and it is very fast. I haven't tried the better light modes. Is this when "baking" happens? To me, it looks just the same as Lumion, but more limited. And you have to do everything is Sketchup...

[Ecuadorian]

As I said, realtime GI is "coming soon" to a future version of LumenRT. Right now, if you want GI in LumenRT you must wait for hours for it to be baked. The fast modes use AO, not GI, similar to Lumion 2.5.

The future "Advanced" version of LumenRT will not be tied to SketchUp. You will be able to import from most 3D software. I found some more info:

Features in LumenRT 3 Advanced
 
Lumen RT Advanced works not only with SketchUp like LumenRT 3 Review but with most 3D applications (including Revit, Bentley, 3ds Max, ArchiCad, AutoCad, Cinema 4D, Vue, etc. ).

Other major improvements :

    Support for multiple light sources
    Ability to create the animation path inside LumenRT
    Content pack already included
    Works with Revit, Bentley, 3ds Max, ArchiCad, AutoCad, Cinema 4D, Vue, etc

Source: http://rfx.com/products/182

[mischa]

GI will be implemented in Lumion 3 !!!! 

[AnilMundi]

Thank you for the clarification, Ecuadorian!

I asked this on the lumneRT forum:

Hello,

I am new to LumeenRT and also trying Lumion to compare. I think the pictures on your website look really beautiful. But I have found this video here:


Can you expalin how this is different from what is called "baking"? And from Lumion?

Thank you.

Here is the answer I got:

Hello Anil,

LumenRT performs a real, physical simulation of light. Because this is an accurate simulation of light, it takes time. This is why, in order to display its best quality, LumenRT requires a preparation phase (referred to as "baking") during which the physical lighting is calculated.
Once this calculation is done, the scene can be displayed in real-time.

However, if you want immediate results without having to wait for the baking, you use the Draft mode. This produces nice results, of similar quality to other products like Lumion. But it doesn't feature realistic lighting. For better lighting, use the more advanced modes (Full lighting) that requires the preparation phase. LumenRT manages to do this physical simulation of light very quickly (typically 15 minutes), despite the staggering complexity involved (e-on holds a number of patents on this technology, so you won't get that elsewhere).

Now what you saw in the video is something different. It's a real-time Global Illumination solution that we have developed and that will be available in a future version of LumenRT. This is not the same as a real, physical simulation of light. What this does is generate a quick approximation of indirect lighting, in real-time. The big advantage of this is that results are instantaneous, and don't require any baking - lighting is updated in real-time, so it reacts immediately to changes in your scene). This is what you see in the video, where the time of day is changed, and you can see the illumination of the building change accordingly. It looks nice, but it is nowhere near as accurate as the physical simulation. Think of it more like a mock-up that gives you "an idea" of what the real simulation might look like.

I hope that clarifies. Let me know if you have any other questions.

So now, I would like to know, is the new GI in Lumion going to be a real physical simulation of light, or a fake solution like above? I tried the physical simulation in LumenRT and it creates really nice lighting which is important for my design, so it is an interesting option. Will this be in Lumion 3?

Thank you

[Ecuadorian]

Judging by my experience with 3dsMAX's radiosity, it seems to me that the LumenRT's "baked GI" is doing this:

-Divide the mesh in small triangles so each new triangle becomes a discrete element. Notice that each linear increase in mesh detail commands a square increase in polygon count.
-Simulate how the light bounces from one triangle to another. This is the phase that takes the
longest.
Unfortunately this method makes it very, very cumbersome to make changes and test variations, since there's no realtime feedback. That's why I have steered clear from LumenRT until now. Once you get used to Lumion's real-time feedback, there's no going back. Also, it's a solution that does not scale well, since you can't have both close-up illumination detail and a huge model.

On the other hand, the realtime GI we saw in the LumenRT Advanced video reminds me of what we had in Artlantis 11 years ago: The software seemed to be placing additional "fill lights" in mid-air. This technique is, of course, a lot less accurate than baking radiosity. I don't know if this is what LumenRT Advanced or Lumion 3.0 are doing... It's up to them to clarify this.

However, neither technique holds a candle to the hottest trend: Realtime GPU-accelerated Pathtracing. Just look on YouTube for Blender Cycles or Octane Render for 3dsmax. Currently it takes a few minutes to clear up the noise in each frame, but in a few years more powerful GPUs, multi-GPU "farms in a box" and better noise-reduction and firefly-clamping algorythms will bring render times down to what we have today in Lumion. Unfortunately, these amazing GPU-accelerated pathtracers are currently only fully integrated with difficult and cumbersome software (Blender, 3dsmax). The day someone integrates Octane or a similar blazing-fast pathtracer with an architectural animation software as easy to use as Lumion... He'll take over the world. Unfortunately it does not exist. Yet.

[AnilMundi]

Wow, thank you again, Ecuadorian. That would be terrific indeed!

Regarding LumenRT, I think their draft mode is the same as Lumion in terms of quality, but you have to go back to Sketchup to modify the scene. so if I want to add some trees around my building, i need to go back to sketchup and export again. It work, but isn't as immediate as Lumion. But when my scene is finished, i can get the nice lighting in Lumenrt. Also, Lumenrt is more limited. But it is a lot cheaper too!

So i like something from each one and I would like to know how good is Lumeion 3 GI?

[Michael Betke]

If you throw in GPU rendering then you may enjoy this:



Dont miss to follow RayTraceys Blog about Brigade:

http://raytracey.blogspot.be/


Its very promising and I think two or three GPUs are not that expesnive theese days but perform well. plu they started to combine the unbiased rendering with post-effects which make it look pretty.

[Ecuadorian]

Thanks for that link.

So OTOY is also behind Brigade? 
No wonder they bought Octane. The only difference seems to be that Brigade is for video game developers (I'm looking at you, Act-3D  ... give OTOY a call!).

The nice thing about these GPU pathtracers is that they scale very well with more hardware. My next PC will have slots for at least two GPUs. 

[Michael Betke]

As far as I know Otoy wants to bring streamed cloud-gaming to the masses. So you play on your ipad for example a AAA game using otoy GPU clusters in the background.

They mix it up with other effects and hired the guy behind iEnhancer who seems to do a great job enhancing GTA IV graphics with his skills.

I have to admit that Octane really picked up speed after the aquisition. More plugins and faster development.

[Remko]

As far as I know Otoy wants to bring streamed cloud-gaming to the masses. So you play on your ipad for example a AAA game using otoy GPU clusters in the background.

And we all know how well that turned out for OnLive

What I never understood about Otoy was the combination of streaming games and real-time ray-tracing. I would say just focus on one thing.

If they could offer real-time ray-tracing that would be enough as a business concept. Upload your scene in 30 minutes and download a fully raytraced movie 30 minutes later. Many people would pay for that.

Imagine you use $1.000.000 worth of computers for 30 minutes and you would have to pay around $100 for that job. Sounds reasonable to me. However, when you start applying the same thing to a tool you use all the time I wonder what the costs would be.

[Remko]

Wow, this is absolutely gorgeous! I checked the LuminRt website and the pictures are incredible. Have you tried it? I'm downloading the trial as we speak. Is this what the new lighting in Lumion 3 is going to be like?

You have to differentiate between real-time and precalculated lighting here. The movie below and Lumion 3.0 both show real-time global illumination. The pictures you refer to precalculated which means the lighting is (slowly) precalculated with algorithms similar to Vray. You can use Vray in combination with Lumion and precalculate the lighting and use the output to get similar results.