9 ms·

Appleseed – open-source physically-based rendering engine

359 points by generic_user 10y ago

wmccullough 10y ago
This looks really beautiful. The fact that it's open source adds to that beauty. I'm not even interested in physically based rendering and it makes me want to play with it.
- generic_user 10y ago
  On the download page there is a bunch of demo scenes that you can simply open and render to see all of the gears and knobs turning and watch your CPUs light up.
- swerner 10y ago
  If you want to learn about state of the art rendering, check out pbrt.org. Even without the book, the source code contains a wealth of information and was written for teaching.
- franzb 10y ago
  Thank you! As generic_user said, feel free to just download a release for your platform and a few test scenes, start appleseed.studio, load a scene and hit F6 to start interactive rendering. The Getting Started page contains detailed instructions: http://appleseedhq.net/docs/tutorials/gettingstarted.html http://appleseedhq.net/docs/tutorials/gettingstarted.html
Mathnerd314 10y ago
2015 Interview with the lead developer: http://blenderdiplom.com/en/interviews/607-interview-francois-beaune-on-appleseed-renderer.html http://blenderdiplom.com/en/interviews/607-interview-francoi... Seems like it's in around the same place, although the plugins are getting better and the renderer is starting to support complex scene features (not quite there yet). Overall though there are 100's of ray-tracers and scene renderers (seemingly all in C++), so it's not clear if it has any compelling advantages.
- erichocean 10y ago
  It's improving regularly, check the GitHub repo. Def. a project to keep an eye on if you're into rendering.
  - Mathnerd314 10y ago
    "Improving" is kind of a strong statement. See for example this recent PR: https://github.com/appleseedhq/appleseed/pull/1217/files https://github.com/appleseedhq/appleseed/pull/1217/files. It seems like they just keep adding and removing special cases, so there's code churn but not really progress in any particular direction...
    - erichocean 10y ago
      Perhaps I'm easier to please. The article your linked to was publish in October 2015. Just this year they've added code[0] to support alSurface[1], which I consider to be a significant (and unexpected) feature improvement. Their news page[2] (to me) shows significant improvements since late 2015 as well, and it looks like the 1.7.x beta is just around the corner[3]. [0] https://github.com/appleseedhq/appleseed/commit/8b0bb02112f7e9e6a4a26882ca6e1e2a2ba98085 https://github.com/appleseedhq/appleseed/commit/8b0bb02112f7... [1] http://www.anderslanglands.com/alshaders/index.html http://www.anderslanglands.com/alshaders/index.html [2] http://appleseedhq.net/news.html http://appleseedhq.net/news.html [3] https://github.com/appleseedhq/appleseed/commit/3dfcad020e0f71fde4015d21e8b39a3daf23e8ac https://github.com/appleseedhq/appleseed/commit/3dfcad020e0f...
      - Mathnerd314 10y ago
        Yeah, there's some progress. But it's slow, compared to other projects. E.g. Tensorflow was released November 2015 and already has 1.7x as many commits and 25x as many committers, and companies like IBM are adding support for it to their toolkits: https://techcrunch.com/2017/01/26/ibm-adds-support-for-googles-tensorflow-to-its-powerai-deep-learning-framework/ https://techcrunch.com/2017/01/26/ibm-adds-support-for-googl... (roughly like what Maya did for Arnold, although Autodesk just bought the whole company: https://www.youtube.com/watch?v=DzoHAhODpi8 https://www.youtube.com/watch?v=DzoHAhODpi8) Maybe it's not possible to make a similar kind of pipeline/platform-type thing for renderers, and they really do need all that material/shader garbage, but I always have been kind of disappointed with the state of the art...
erichocean 10y ago
Here are some render comparisons for the curious: http://appleseedhq.net/stuff/renderers-comparison/index.html http://appleseedhq.net/stuff/renderers-comparison/index.html
- fizixer 10y ago
  - I've never heard of Tungsten. - Mitsuba is a mainly-academic renderer by Wenzel Jakob (I say mainly because I haven't seen its widespread use in non-academic setting). The two important open source renderers that are missing in comparison: - Cycles (comes with Blender; produces great results although it is said that it only recently has started doing a "PBR workflow") - Luxrender (very popular with artists on deviantart; has very good OpenCL support)
  - erichocean 10y ago
    That's because the point of the comparison is not to compare with other renderers, it's to check feature correctness. Mitsuba is widely used for that purpose. Almost no one uses LuxRender or Cycles commercially to the best of my knowledge (or appleseed for that matter). Hobbyists use them, which is cool. I'm in Los Angeles and work in the industry. Here, people use Renderman, Arnold, and in-house stuff mostly. I don't think Renderman and Arnold are used much outside of VFX. Arnold in particular is pricey, but works amazingly well.
    - horse3d 10y ago
      Few people use Blender professionally, but those that do almost certainly will use Cycles. It's very capable now, quite similar to Arnold, but not as fast.
      - sdwisely 10y ago
        It's still desirable enough that it's getting commercial plugins (cycles4d).
    - santaclaus 10y ago
pasta 10y ago
If you like this you also might like Luxrender. Also an open source physically based render engine: http://www.luxrender.net/ http://www.luxrender.net/
redpanda_ua 10y ago
It's all cool and awesome, but why put all those resources into new renderer, when one could contribute to Blender and such, which are way more mature?
- hellofunk 10y ago
  Two points: Blender is not a renderer, it's a modelling and animation program with a built-in renderer, Cycles. But it can connect to other renderers, too. Cycles is not that old. It replaced Blender's prior renderer just a few years ago.
  - object_destroy 10y ago
    Appleseed has also been under active development for 7+ years; so not that young, especially considering that physically-based renders really only started coming into full production use 3-4 years ago. There are still many visual effects studios using approximation-based setups today, so I'd say there's lots of room for "new renderers" to carve their niche.
  - redpanda_ua 10y ago
    I know Blender is not a renderer, but they include 3 renderers in the package: Bledner Internal, Cycles and, Blender Game (This one is Real-Time though).
- swerner 10y ago
  1. Because it's fun. 2. Because you're using a different program than blender. 3. Because you want to work on code that you know wouldn't get accepted in the blender code base anyway. 4. Because you can. I have contributed patches to Blender that got accepted. Even I feel the urge to write my own render engine, to try out different approaches and just so I can claim "I wrote that".
flixic 10y ago
There are quite a few interesting options for 3D, what is the best thing for 2D? Fast open source 2d rendering engine? Is Skia pretty much the only option?
- santaclaus 10y ago
  I've seen Cairo and Antigrain used in the wild for 2D rendering, too.
object_destroy 10y ago
If you're into graphics pipelines, here's a few interesting videos of Gaffer node networks rendering with Appleseed: http://www.gafferhq.org/demos/ http://www.gafferhq.org/demos/
- softwarelimits 10y ago
  how does gaffer compare to BMD Fusion? Thanks! BTW it would be really great if the webmaster of gafferhq.org considered to add some contrast to the parts of the website that should be read by visitors. (aka http://contrastrebellion.com/ http://contrastrebellion.com/ )
softwarelimits 10y ago
what happened with the Ramen compositor?
kkapelon 10y ago
The name clashes with a well known anime movie, which also uses CGI. Maybe change the name of this engine?
- franzb 10y ago
  Think of it has a homage! :)
  - franzb 10y ago
    (as a homage, sorry)
- Narann 10y ago
  The renderer is lowercase is that purpose. ;)
franzb 10y ago
Hello, founder of appleseed here! Being the top story on Hacker News tonight was completely unexpected, but it's a good surprise and definitely appreciated publicity! appleseed has been in active development since june of 2009. It predates a number of other open source renderers by quite a few years, including Cycles (another fantastic project!). I'm a production rendering engineer (e-on software, mental images, NVIDIA, Jupiter Jazz...). I've started this project out of personal interest for rendering, and as a platform for learning (there's always tons of new stuff to learn), research and experiments. All other team members are professionals currently working in the industry. appleseed is one of the few open source renderers designed for production rendering and targeted at animation and VFX. In addition to fully programmable shading via OpenShadingLanguage, strong support for motion blur and many other specific features, it supports accurate spectral rendering, which is quite a unique combination. We still have a ton of work ahead to make it a truly competitive renderer but we're making regular progress: we're improving the core renderer every day, and lately we've been putting massive efforts in improving our integration with DCC apps and in achieving a comfortable workflow for artists. Loads left to do ! Let me finally add that I'm blessed to work with such a great team. Top quality work, persistently. We're a small but welcoming community, and contributions are most welcome! Feel free to ask me anything!
- generic_user 10y ago
  Can you list the top five Influential research papers that have inspired you while working on Appleseed? I have ACM library account so if they are ACM or Siggraph papers that is fine. --edit And thank you for making your project open source.
  - franzb 10y ago
    A very interesting question! It's not a research paper, but for learning purposes there's nothing better than the Physically-Based Rendering (PBRT) book by Matt Pharr, Greg Humphreys and Wenzel Jakob, already mentioned by others in this thread: http://www.pbrt.org/ http://www.pbrt.org/ One of the foundational paper is definitely The Rendering Equation, by James Kajiya: https://inst.eecs.berkeley.edu/~cs294-13/fa09/lectures/p143-kajiya.pdf https://inst.eecs.berkeley.edu/~cs294-13/fa09/lectures/p143-... Another highly influencial research paper is certainly Eric Veach's PhD thesis, Robust Monte Carlo Methods For Light Transport Simulation (a.k.a. "The Bible"): http://graphics.stanford.edu/papers/veach_thesis/thesis.pdf http://graphics.stanford.edu/papers/veach_thesis/thesis.pdf A few other paper stand out: Understanding the Masking-Shadowing Function in Microfacet-Based BRDFs, by Eric Heitz: http://jcgt.org/published/0003/02/03/ http://jcgt.org/published/0003/02/03/. A somewhat difficult read, but an important paper. Microfacet Models for Refraction through Rough Surfaces: http://www.cs.cornell.edu/~srm/publications/EGSR07-btdf.pdf http://www.cs.cornell.edu/~srm/publications/EGSR07-btdf.pdf Physically-Based Shading at Disney: https://disney-animation.s3.amazonaws.com/library/s2012_pbs_disney_brdf_notes_v2.pdf https://disney-animation.s3.amazonaws.com/library/s2012_pbs_... A Practical Model for Subsurface Light Transport, by Henrik Wann Jensen: https://graphics.stanford.edu/papers/bssrdf/bssrdf.pdf https://graphics.stanford.edu/papers/bssrdf/bssrdf.pdf Light Transport Simulation with Vertex Connection and Merging: http://cgg.mff.cuni.cz/~jaroslav/papers/2012-vcm/ http://cgg.mff.cuni.cz/~jaroslav/papers/2012-vcm/ Finally, for learning, there's a nice lecture by John Carmack at QuakeCon: https://www.youtube.com/watch?v=IyUgHPs86XM https://www.youtube.com/watch?v=IyUgHPs86XM
skratlo 10y ago
No word on GPU acceleration?
lawnchair_larry 10y ago
Can someone Explain Like I'm Five: "Physically-based rendering"? As opposed to...?
- gribbly 10y ago
  Non-physically based rendering :) Kidding aside, as I understand it (I'm certainly no expert), the terms most often used are biased versus unbiased rendering, were biased has artificial limitations, while unbiased employs 'real world' calculations. So why use biased renderers ? Well they can typically create a very good result using much less time compared to a unbiased renderer, on the other hand they typically also require that you mess around with a lot of knobs in order to get good results, meanwhile with a unbiased renderer you can just set up a 'real world' scene and it will render as such (albeit more slowly). My guess is that Renderman is the most widely used biased renderer today, with Arnold being the most used unbiased.
  - berkut 10y ago
    That's not really what 'biased' and 'unbiased' mean - unfortunately the terms have been miss-used quite a bit, and are actually open to interpretation to a degree anyway. You can have biased physically-based rendering and you can have unbiased 'not quite physically-based' rendering - in the latter case for example, it's possible to render direct lighting only (so no secondary bounces, or global illumination), which while obviously not the correct real result in physical terms, to the extent that you're evaluating direct lighting only the result is technically unbiased in terms of light transport. Similarly, it's possibly to have a spectral renderer (which in theory should be more accurate) which is biased, and a non-spectral renderer (RGB only) which is unbiased. Biased can mean things like taking short-cuts or approximations - e.g. irradiance caches for diffuse results, or caching occlusion in order to slightly bias which light to sample per vertex in order to sample lights more efficiently: Both of these biased techniques generally give faster less noisy renders, but it's possible you might not notice they are biased in terms of the effect they have on the render - it all depends on the scene, materials and the lighting. For simple scenes you probably won't notice, for more complex scenes with nested medium materials with glossy/pure specular responses or with refractive caustics, it's very likely you will notice the effects biased rendering has compared to unbiased rendering. Renderman RIS can be set up to be unbiased (but with default settings - radiance clamps) it's not. Similarly Arnold's default settings of having a light threshold (under which it won't sample a light) is also biased, but obviously this setting can be changed. Arnold can also cache diffuse contributions on hair, which is also biased.
TOGoS 10y ago
Hierarchical instancing YEAAHHH!!!! Thanks guys; I no longer need to go write my own path tracer. (I say this because I really like the idea of things like Chunky (the pathtracer for Minecraft), but I'd rather be able to simply export data to a more mature, full-featured renderer. Hierarchical instancing means you can do things like make bricks out of grains of sand, make brick blocks out of bricks, etc, without /necessarily/ blowing your memory budget when rendering a large map.)
hollywoodlife 10y ago
Super Bowl 2017 Live Stream Free https://www.linkedin.com/pulse/watch-nfl-2017-super-bowl-live-stream-free-frances-xiong https://www.linkedin.com/pulse/watch-nfl-2017-super-bowl-liv...

359 points by generic_user 10y ago

This looks really beautiful. The fact that it's open source adds to that beauty. I'm not even interested in physically based rendering and it makes me want to play with it.

generic_user 10y ago
On the download page there is a bunch of demo scenes that you can simply open and render to see all of the gears and knobs turning and watch your CPUs light up.
swerner 10y ago
If you want to learn about state of the art rendering, check out pbrt.org. Even without the book, the source code contains a wealth of information and was written for teaching.
franzb 10y ago
Thank you! As generic_user said, feel free to just download a release for your platform and a few test scenes, start appleseed.studio, load a scene and hit F6 to start interactive rendering. The Getting Started page contains detailed instructions: http://appleseedhq.net/docs/tutorials/gettingstarted.html http://appleseedhq.net/docs/tutorials/gettingstarted.html

Mathnerd314 10y ago

2015 Interview with the lead developer: http://blenderdiplom.com/en/interviews/607-interview-francois-beaune-on-appleseed-renderer.html http://blenderdiplom.com/en/interviews/607-interview-francoi... Seems like it's in around the same place, although the plugins are getting better and the renderer is starting to support complex scene features (not quite there yet). Overall though there are 100's of ray-tracers and scene renderers (seemingly all in C++), so it's not clear if it has any compelling advantages.

erichocean 10y ago
It's improving regularly, check the GitHub repo. Def. a project to keep an eye on if you're into rendering.
- Mathnerd314 10y ago
  "Improving" is kind of a strong statement. See for example this recent PR: https://github.com/appleseedhq/appleseed/pull/1217/files https://github.com/appleseedhq/appleseed/pull/1217/files. It seems like they just keep adding and removing special cases, so there's code churn but not really progress in any particular direction...
  - erichocean 10y ago
    Perhaps I'm easier to please. The article your linked to was publish in October 2015. Just this year they've added code[0] to support alSurface[1], which I consider to be a significant (and unexpected) feature improvement. Their news page[2] (to me) shows significant improvements since late 2015 as well, and it looks like the 1.7.x beta is just around the corner[3]. [0] https://github.com/appleseedhq/appleseed/commit/8b0bb02112f7e9e6a4a26882ca6e1e2a2ba98085 https://github.com/appleseedhq/appleseed/commit/8b0bb02112f7... [1] http://www.anderslanglands.com/alshaders/index.html http://www.anderslanglands.com/alshaders/index.html [2] http://appleseedhq.net/news.html http://appleseedhq.net/news.html [3] https://github.com/appleseedhq/appleseed/commit/3dfcad020e0f71fde4015d21e8b39a3daf23e8ac https://github.com/appleseedhq/appleseed/commit/3dfcad020e0f...
    - Mathnerd314 10y ago
      Yeah, there's some progress. But it's slow, compared to other projects. E.g. Tensorflow was released November 2015 and already has 1.7x as many commits and 25x as many committers, and companies like IBM are adding support for it to their toolkits: https://techcrunch.com/2017/01/26/ibm-adds-support-for-googles-tensorflow-to-its-powerai-deep-learning-framework/ https://techcrunch.com/2017/01/26/ibm-adds-support-for-googl... (roughly like what Maya did for Arnold, although Autodesk just bought the whole company: https://www.youtube.com/watch?v=DzoHAhODpi8 https://www.youtube.com/watch?v=DzoHAhODpi8) Maybe it's not possible to make a similar kind of pipeline/platform-type thing for renderers, and they really do need all that material/shader garbage, but I always have been kind of disappointed with the state of the art...

erichocean 10y ago

Here are some render comparisons for the curious: http://appleseedhq.net/stuff/renderers-comparison/index.html http://appleseedhq.net/stuff/renderers-comparison/index.html

fizixer 10y ago
- I've never heard of Tungsten. - Mitsuba is a mainly-academic renderer by Wenzel Jakob (I say mainly because I haven't seen its widespread use in non-academic setting). The two important open source renderers that are missing in comparison: - Cycles (comes with Blender; produces great results although it is said that it only recently has started doing a "PBR workflow") - Luxrender (very popular with artists on deviantart; has very good OpenCL support)
- erichocean 10y ago
  That's because the point of the comparison is not to compare with other renderers, it's to check feature correctness. Mitsuba is widely used for that purpose. Almost no one uses LuxRender or Cycles commercially to the best of my knowledge (or appleseed for that matter). Hobbyists use them, which is cool. I'm in Los Angeles and work in the industry. Here, people use Renderman, Arnold, and in-house stuff mostly. I don't think Renderman and Arnold are used much outside of VFX. Arnold in particular is pricey, but works amazingly well.
  - horse3d 10y ago
    Few people use Blender professionally, but those that do almost certainly will use Cycles. It's very capable now, quite similar to Arnold, but not as fast.
    - sdwisely 10y ago
      It's still desirable enough that it's getting commercial plugins (cycles4d).
  - santaclaus 10y ago

pasta 10y ago

If you like this you also might like Luxrender. Also an open source physically based render engine: http://www.luxrender.net/ http://www.luxrender.net/

redpanda_ua 10y ago

It's all cool and awesome, but why put all those resources into new renderer, when one could contribute to Blender and such, which are way more mature?

hellofunk 10y ago
Two points: Blender is not a renderer, it's a modelling and animation program with a built-in renderer, Cycles. But it can connect to other renderers, too. Cycles is not that old. It replaced Blender's prior renderer just a few years ago.
- object_destroy 10y ago
  Appleseed has also been under active development for 7+ years; so not that young, especially considering that physically-based renders really only started coming into full production use 3-4 years ago. There are still many visual effects studios using approximation-based setups today, so I'd say there's lots of room for "new renderers" to carve their niche.
- redpanda_ua 10y ago
  I know Blender is not a renderer, but they include 3 renderers in the package: Bledner Internal, Cycles and, Blender Game (This one is Real-Time though).
swerner 10y ago
1. Because it's fun. 2. Because you're using a different program than blender. 3. Because you want to work on code that you know wouldn't get accepted in the blender code base anyway. 4. Because you can. I have contributed patches to Blender that got accepted. Even I feel the urge to write my own render engine, to try out different approaches and just so I can claim "I wrote that".

flixic 10y ago

There are quite a few interesting options for 3D, what is the best thing for 2D? Fast open source 2d rendering engine? Is Skia pretty much the only option?

santaclaus 10y ago
I've seen Cairo and Antigrain used in the wild for 2D rendering, too.

object_destroy 10y ago

If you're into graphics pipelines, here's a few interesting videos of Gaffer node networks rendering with Appleseed: http://www.gafferhq.org/demos/ http://www.gafferhq.org/demos/

softwarelimits 10y ago
how does gaffer compare to BMD Fusion? Thanks! BTW it would be really great if the webmaster of gafferhq.org considered to add some contrast to the parts of the website that should be read by visitors. (aka http://contrastrebellion.com/ http://contrastrebellion.com/ )

softwarelimits 10y ago

what happened with the Ramen compositor?

kkapelon 10y ago

The name clashes with a well known anime movie, which also uses CGI. Maybe change the name of this engine?

franzb 10y ago
Think of it has a homage! :)
- franzb 10y ago
  (as a homage, sorry)
Narann 10y ago
The renderer is lowercase is that purpose. ;)

franzb 10y ago

Hello, founder of appleseed here! Being the top story on Hacker News tonight was completely unexpected, but it's a good surprise and definitely appreciated publicity! appleseed has been in active development since june of 2009. It predates a number of other open source renderers by quite a few years, including Cycles (another fantastic project!). I'm a production rendering engineer (e-on software, mental images, NVIDIA, Jupiter Jazz...). I've started this project out of personal interest for rendering, and as a platform for learning (there's always tons of new stuff to learn), research and experiments. All other team members are professionals currently working in the industry. appleseed is one of the few open source renderers designed for production rendering and targeted at animation and VFX. In addition to fully programmable shading via OpenShadingLanguage, strong support for motion blur and many other specific features, it supports accurate spectral rendering, which is quite a unique combination. We still have a ton of work ahead to make it a truly competitive renderer but we're making regular progress: we're improving the core renderer every day, and lately we've been putting massive efforts in improving our integration with DCC apps and in achieving a comfortable workflow for artists. Loads left to do ! Let me finally add that I'm blessed to work with such a great team. Top quality work, persistently. We're a small but welcoming community, and contributions are most welcome! Feel free to ask me anything!

generic_user 10y ago
Can you list the top five Influential research papers that have inspired you while working on Appleseed? I have ACM library account so if they are ACM or Siggraph papers that is fine. --edit And thank you for making your project open source.
- franzb 10y ago
  A very interesting question! It's not a research paper, but for learning purposes there's nothing better than the Physically-Based Rendering (PBRT) book by Matt Pharr, Greg Humphreys and Wenzel Jakob, already mentioned by others in this thread: http://www.pbrt.org/ http://www.pbrt.org/ One of the foundational paper is definitely The Rendering Equation, by James Kajiya: https://inst.eecs.berkeley.edu/~cs294-13/fa09/lectures/p143-kajiya.pdf https://inst.eecs.berkeley.edu/~cs294-13/fa09/lectures/p143-... Another highly influencial research paper is certainly Eric Veach's PhD thesis, Robust Monte Carlo Methods For Light Transport Simulation (a.k.a. "The Bible"): http://graphics.stanford.edu/papers/veach_thesis/thesis.pdf http://graphics.stanford.edu/papers/veach_thesis/thesis.pdf A few other paper stand out: Understanding the Masking-Shadowing Function in Microfacet-Based BRDFs, by Eric Heitz: http://jcgt.org/published/0003/02/03/ http://jcgt.org/published/0003/02/03/. A somewhat difficult read, but an important paper. Microfacet Models for Refraction through Rough Surfaces: http://www.cs.cornell.edu/~srm/publications/EGSR07-btdf.pdf http://www.cs.cornell.edu/~srm/publications/EGSR07-btdf.pdf Physically-Based Shading at Disney: https://disney-animation.s3.amazonaws.com/library/s2012_pbs_disney_brdf_notes_v2.pdf https://disney-animation.s3.amazonaws.com/library/s2012_pbs_... A Practical Model for Subsurface Light Transport, by Henrik Wann Jensen: https://graphics.stanford.edu/papers/bssrdf/bssrdf.pdf https://graphics.stanford.edu/papers/bssrdf/bssrdf.pdf Light Transport Simulation with Vertex Connection and Merging: http://cgg.mff.cuni.cz/~jaroslav/papers/2012-vcm/ http://cgg.mff.cuni.cz/~jaroslav/papers/2012-vcm/ Finally, for learning, there's a nice lecture by John Carmack at QuakeCon: https://www.youtube.com/watch?v=IyUgHPs86XM https://www.youtube.com/watch?v=IyUgHPs86XM

skratlo 10y ago

No word on GPU acceleration?

lawnchair_larry 10y ago

Can someone Explain Like I'm Five: "Physically-based rendering"? As opposed to...?

gribbly 10y ago
Non-physically based rendering :) Kidding aside, as I understand it (I'm certainly no expert), the terms most often used are biased versus unbiased rendering, were biased has artificial limitations, while unbiased employs 'real world' calculations. So why use biased renderers ? Well they can typically create a very good result using much less time compared to a unbiased renderer, on the other hand they typically also require that you mess around with a lot of knobs in order to get good results, meanwhile with a unbiased renderer you can just set up a 'real world' scene and it will render as such (albeit more slowly). My guess is that Renderman is the most widely used biased renderer today, with Arnold being the most used unbiased.
- berkut 10y ago
  That's not really what 'biased' and 'unbiased' mean - unfortunately the terms have been miss-used quite a bit, and are actually open to interpretation to a degree anyway. You can have biased physically-based rendering and you can have unbiased 'not quite physically-based' rendering - in the latter case for example, it's possible to render direct lighting only (so no secondary bounces, or global illumination), which while obviously not the correct real result in physical terms, to the extent that you're evaluating direct lighting only the result is technically unbiased in terms of light transport. Similarly, it's possibly to have a spectral renderer (which in theory should be more accurate) which is biased, and a non-spectral renderer (RGB only) which is unbiased. Biased can mean things like taking short-cuts or approximations - e.g. irradiance caches for diffuse results, or caching occlusion in order to slightly bias which light to sample per vertex in order to sample lights more efficiently: Both of these biased techniques generally give faster less noisy renders, but it's possible you might not notice they are biased in terms of the effect they have on the render - it all depends on the scene, materials and the lighting. For simple scenes you probably won't notice, for more complex scenes with nested medium materials with glossy/pure specular responses or with refractive caustics, it's very likely you will notice the effects biased rendering has compared to unbiased rendering. Renderman RIS can be set up to be unbiased (but with default settings - radiance clamps) it's not. Similarly Arnold's default settings of having a light threshold (under which it won't sample a light) is also biased, but obviously this setting can be changed. Arnold can also cache diffuse contributions on hair, which is also biased.

TOGoS 10y ago

Hierarchical instancing YEAAHHH!!!! Thanks guys; I no longer need to go write my own path tracer. (I say this because I really like the idea of things like Chunky (the pathtracer for Minecraft), but I'd rather be able to simply export data to a more mature, full-featured renderer. Hierarchical instancing means you can do things like make bricks out of grains of sand, make brick blocks out of bricks, etc, without /necessarily/ blowing your memory budget when rendering a large map.)

hollywoodlife 10y ago

Super Bowl 2017 Live Stream Free https://www.linkedin.com/pulse/watch-nfl-2017-super-bowl-live-stream-free-frances-xiong https://www.linkedin.com/pulse/watch-nfl-2017-super-bowl-liv...