New MetropoLight (free MLT renderer) release 0.6.0

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New MetropoLight (free MLT renderer) release 0.6.0

Post by albedo »

Hello everyone !

I wanted to let you know that I made my last short project MetropoLight freely available to the public. It seems to be the very first "private" GI rendering engine using the Metropolis Light Transport algorithm. MetropoLight doesn't claim to be a sophisticated renderer (such as my other renderer VirtuaLight). It just has to be considered as an experimental rendering tool. Some of its features are:

* Support for smooth triangle primitive.
* Support for phong BRDF model.
* Support for point light.
* Support for camera exposure responsivity.
* Support for tone mapping.
* Support for UV texture mapping (Targa, PNG, TIFF, BMP, PFM & HDR).
* Support for High Dynamic Range output (HDR) or 24-bit Targa image.
* Efficient BSP tree for fast ray/triangle intersections.
* Internal colors as a sampled spectrum.
* OpenGL Window framebuffer displaying progressive refinement of the solution.

web site is:

I'm planning on implementing a bunch of other features in order to complete this project.
Currently, only export plug-ins are available for Maya and 3DS (written by me). I'd be glad to see an export script for Blender, but I'm not familiar enough with its language for such a task. I'm sure that both free programs could make interesting "experimental" images thanks to the Blender community.
If one of you all is interested in writing such a script, please keep us posted!
MetropoLight uses a very simple input format (close to Wavefront .OBJ) in order to make it easily accessible.

Thanks for reading me, and enjoy !

Stephane Marty

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Post by Toon_Scheur »

Hi, I've seen your post in CGTALK and some reactions were unnecessary harsh. MLT defitnely has some perspective. Sure the pics looks grainy and the render times are too long, but since this is experimental, it means that there ample room for improvements in quality and renderspeed.

I would like to see how it performs once it is fully mature.


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Post by Sutabi »

Makes me think of WinOSI, I'd like to see this develop more ^_^.

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Post by Koba »

Wow...Stephane Marty on Blender forums..

Anyway, I've been following virtualight for ages and ages - It has always been one of my favorite free GI renderers (other than yafray) and I still have a softspot for it. I remember when you announced MLT and I was quite excited about it. That was years ago now...I checked the website for a couple of months but eventually gave up. It is nice to see the project isn't dead! In fact I'm testing it out right now.

There used to be a virtualight script for blender (dotblend I think it was) but I don't think it works anymore. At one point I was about to write a new script for Virtualight 1.40 but then the toxic renderer caught my eye (sadly a dead project now). At least I learnt some useful things from my toxic script while I was waiting for VirtuaLight A.E.R.E...

On that subject....will VirtuaLight A.E.R.E ever be released? I was really looking forward to it when it was announced (with the new license and linux support) but I have since given up on that too. :(


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Post by poutsa »

Last edited by poutsa on Mon Sep 05, 2005 10:18 am, edited 1 time in total.

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Post by joeri »

poutsa wrote:Is this Full GI and SSS Internal Blender Rendering still in Development or not? (quote edited to be more readable)
> Please don't hyjack this thread, a new question fits best in a new thread.

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Post by albedo »

Well, VirtuaLight A.E.R.E. is a different story...

I'm not going to give details about it, but for now, it's still a work in progress. But I have a kind of dilem... if everything goes right, A.E.R.E. will have state-of-the-art rendering technology when released, with advanced unbiased algorithms. The very first images I got are quite impressive, I never obtained such realistic renders with VirtuaLight.
So, people around me keep asking me why I chose to release it for free instead of distribute it under license. Well, I'm just questionning myself.
You know what I mean...

BTW, A.E.R.E. (Advancad Experimental Rendering Engine) is a codename. I don't think that the final product will keep the name 'VirtuaLight'.


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Post by Koba »

I understand perfectly well where you are coming from and I understand the pressure you are feeling.

It is so sad to see so many great projects get abandoned due to commercial pressures (toxic is on my mind as well). CG is a very expensive field and I am so very happy to have been able to persue my hobby using free tool only (and mainly open-source at that).

In my opinion you should release AERE for free if when you coded it you were doing it for your own enjoyment and without commercial aims in mind. In a sense, if you wrote AERE for your own benefit, for whatever reason, you should stick with that in mind and release it freely which would make many people very happy (and you could have the satisfaction of seeing other people use and enjoy your work). If you wrote with the intention of making money, then selling it is more than fair play.

Why not charge for exporters to AERE from commercial packages (such a 3D Studio Max, Maya etc) while leaving the standalone renderer free? People using commercial packages are probably professionals and should be willing to pay for such a thing. I'm thinking along the lines of Raypack for Truespace: that was a paying product with a truespace exporter to Virtualight (I believe)

Naturally, I would love to see AERE free but in the end what you do with it is your own choice.


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Post by lusque »

Well, there's another option if you don't want to put AERE under the GPL. You can double-license your renderer: free for personal use and a paying license for commercial use, like AVG antivirus or ZoneAlarm Firewall.

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Post by albedo »

lusque wrote:Well, there's another option if you don't want to put AERE under the GPL. You can double-license your renderer: free for personal use and a paying license for commercial use, like AVG antivirus or ZoneAlarm Firewall.
Yes, I did that too for VirtuaLight. It became freeware from release 1.4 only.
But the problem here is a bit more complicated, and it is off-topic too ;)


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open source

Post by bfvietnam »

I think it depends a lot on how you market what you make, if its very popular, you might try to commercialize it, if that affects the popularity you might go back to shareware/freeware.. If the technique is revolutionary but not popular and the market is going in the wrong direction, you feel, you may try to open source it and work on making it more useful to other developers.

I believe Open Sourcing code is the best way to standardize because it makes it incredibly difficult to ignore and it gives developers a point of reference to determine if a commercialized project is veering from logic for selfish intent (vendor lockin). It also would help distinguish between proprietary technologies that are better and proprietary technologies that are different.

A common technique of "widget" sales, like people who make and sell kitchenware, such as spoons, is to change the shape or the color of the spoon. These are changes of difference, its hard to tell if these changes make the product better, they just give you a choice.. But if its a spoon that preserves the heat of its contents, it adds something to a spoon that is not normal.

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