December 2014 - Pharo-dev - lists.pharo.org

Re: [Pharo-dev] Smalltalk Reflections Podcast

by davidbuck

Thanks Stef. One possibility is to get a few Pharo developers together to have a short round-table talking about Pharo and we'd insert that as a segment into the podcast. We're open to all sorts of possibilities. David -- View this message in context: http://forum.world.st/Smalltalk-Reflections-Podcast-tp4797444p4797493.html Sent from the Pharo Smalltalk Developers mailing list archive at Nabble.com.

Dec. 31, 2014

Re: [Pharo-dev] Smalltalk Reflections Podcast

by davidbuck

We do this already with the Smalltalk Jobs Report by James T. Savidge. Craig and I discuss some topic for half an hour and record the session. Separately, we have James record a short 1 or 2 minute segment on Smalltalk Jobs and send the audio of just him speaking. We then mix that into the episode at some nice breaking point with an introduction like "Now, here's James Savidge with the Smalltalk Jobs Report". We can do that with other segments as well if people want to produce them. Alternatively, we can bring someone into the podcast and record in a conversational style. The small issue here is simply scheduling and time zones. I'm in Ottawa Canada and Craig is in Amsterdam so there's already a six hour time difference. To bring someone else into the conversation may make it harder to schedule because of time zones but we're happy to try it. David -- View this message in context: http://forum.world.st/Smalltalk-Reflections-Podcast-tp4797444p4797492.html Sent from the Pharo Smalltalk Developers mailing list archive at Nabble.com.

Dec. 31, 2014

Re: [Pharo-dev] Jun4Pharo so exciting :)

by kilon alios

Oh I am not complaining at all, your work is very inspiring , afterall what good Pharo is if one does not create code in it. Nor I would be a happy pharoer that I would need to code in javascript to improve / extend Roassal . Or modify C source code to make Athens 3D. My case is a bit special that my demands graphics wise are extremely high , since high end 3d is my main area of focus. I think in the end both roads can be very beneficial, huge libraries used by Pharo but because they are not made in Pharo will be harder to extend but with more features. Smaller pharo libraries that come with fewer features but are much easier to improve because they are coded completely in pharo. No such thing as ideal choice, everything comes with its advantages and disadvantages. On Wed, Dec 31, 2014 at 3:07 PM, Alexandre Bergel <alexandre.bergel(a)me.com> wrote: > My email was more an encouragement than anything else :-) > > Alexandre > > > > On Dec 31, 2014, at 1:06 PM, kilon alios <kilon.alios(a)gmail.com> wrote: > > > > not if the task is huge > > > > To give you an idea about the diffirence in size > > > > https://www.openhub.net/p/d3js > > > > https://www.openhub.net/p/blender > > > > you are a team of full time , very experienced pharo coders (correct me > if i am wrong) > > > > me I am a part time newcomer to pharo. > > > > On Wed, Dec 31, 2014 at 1:59 PM, Alexandre Bergel < > alexandre.bergel(a)me.com> wrote: > > Well... The hard way is very gratifying. We could have worked on an > integration of D3 in Pharo instead of working on Roassal :) > > > > Alexandre > > > > EnvoyÃ© de mon iPhone > > > > Le 31 dÃ©c. 2014 Ã 11:38, kilon alios <kilon.alios(a)gmail.com> a Ã©crit : > > > >> I dont doubt for a minute it will be a difficult task , this is why I > chose not to do it and instead I went down the easy route of relying on > existing graphics engines in my case Blender which I try to expose it to > Pharo. I learned the hard way how much time one can waste doing things the > hard way. > >> > >> On Tue, Dec 30, 2014 at 10:59 PM, Ronie Salgado <roniesalg(a)gmail.com> > wrote: > >> Is this a real concern ? Afterall vector data is a lot less complex > than 3d geometry and CPUs nowdays are multicore. > >> For really smooth and complex animations, yes it is a concern. > Performance. If the objective is to draw a static shape or a slow > animation, it is not a big problem. Also CPU <-> GPU data transferring is > an expensive operation that has to be avoided if possible. > >> > >> Actually 2D vector data is more complex. 3D geometry comes already > processed to be directly rendered, and it is represented by only two > arrays: vertices and indices. > >> > >> In contrast, 2D vector data is represented by a stream of commands that > have to be evaluated. > >> > >> BTW, we don't have support for real multithreading in Pharo, and we > will not have it for a very long time. The closest thing to real > multithreading that we are getting in the near term > >> Don't know about the Opengl backend of Cairo. Igor also once shown me a > Spec for vector graphics on OpenGL by Khronos Group. > >> Well, there is OpenVG designed for mobile platform(Android and iOS). > OpenVG is not supported by desktop graphic cards vendors. > >> > >> The closest thing we have in the desktop world is the NV_path_rendering > NVIDIA only extension. At least the paper that describes this extension is > really good. The bad thing is that it depends at least partially in the > Loop-Blinn algorithm that is patented, if I remember right. > >> > >> Newest OpenGL versions also come with dynamic tesselation geometry > shaders that basically increase the detail of a 3d object the closer a > camera gets to it which is similar to vector graphics which is something > that could also work as basic via NBOpenGL to bring Athens to 3d side > completely bypassing Cairo. > >> > >> In first place, not all of the world have at least DX11/OpenGL 4.xx > level graphic card. But, it does not matter too much because the hardware > tessellation does not help you anything with the main problem. > >> > >> The biggest problem is that 2D vector paths can be concave, and they > can have a hole . The easiest way to support it is by using the stencil > buffer, and in my opinion is the method with the better results. In fact, > the NV_path_rendering extension is implemented in this way, but directly in > the OpenGL driver. > >> > >> This method renders first the tessellated path with a triangle fan, > with the stencil test set to invert the stencil buffer bits. In this way, > the stencil buffer holds 1 in the points that are inside of the path, and 0 > in the points that are outside of the path. > >> > >> Then, the bounding box of the path is covered with fill color/gradient, > but with the stencil test set to only pass when the stencil buffer value is > 1, and to also clear the stencil buffer in the covered region during the > process to allow rendering more paths elements. > >> > >> Each one of the changes to the way the stencil buffer is used involves > a state change, which is expensive. I think this is the reason of why > NVIDIA implemented their extension directly in the OpenGL. > >> > >> I know of these problems because I implemented once the stencil method > in C++ with OpenGL. > >> > >> The old opengl Cairo backend worked by triangulating the paths. > Triangulation of concave geometry is hard to do, and there some degenerate > case in which it produces bad results. > >> > >> Best regards > >> Ronie > >> > >> 2014-12-30 16:58 GMT-03:00 kilon alios <kilon.alios(a)gmail.com>: > >> > >> Is this a real concern ? Afterall vector data is a lot less complex > than 3d geometry and CPUs nowdays are multicore. > >> > >> Don't know about the Opengl backend of Cairo. Igor also once shown me a > Spec for vector graphics on OpenGL by Khronos Group. > >> > >> So there are alternatives but as always it will require someone doing > the hard work to bring that functionality to Pharo. > >> > >> Newest OpenGL versions also come with dynamic tesselation geometry > shaders that basically increase the detail of a 3d object the closer a > camera gets to it which is similar to vector graphics which is something > that could also work as basic via NBOpenGL to bring Athens to 3d side > completely bypassing Cairo. > >> > >> On Tue, Dec 30, 2014 at 9:18 PM, Ronie Salgado <roniesalg(a)gmail.com> > wrote: > >> Athens uses Cairo , Cairo can be used with OpenGL. You can use Cairo to > apply a 2d vector graphic as a texture to a 3d polygon. Cairo website shows > several examples of this. That means its possible to have 2d vector > graphics in 3d space as if its true 3d. > >> I do not think that is going to work easily with the best performance > possible. Cairo could be using OpenGL, but probably in a different OpenGL > than the one that is being used for 3d graphics. > >> > >> In addition, the Cairo OpenGL backend is experimental ( > http://cairographics.org/OpenGL/) . Currently you have to render into a > surface in CPU, then transfer it into GPU and then render the polygon. A > naive version using the OpenGL backend is going to have GPU->CPU->GPU > roundtrip > >> > >> If we are using this route, I think that is better to just use the > current version of Athens for this. With Athens we can render into a Form, > which can be used to populate a Woden/Roassal texture or transferred > directly to OpenGL. This has the advantage of not having a explicit > dependency in Cairo. I guess that I will make a demo of this later. It > should be easy. > >> > >> I think that a longer term approach could be having a custom renderer, > tailored for Athens using OpenGL or maybe OpenCL. > >> > >> 2D vector graphics are really hard. In my opinion they are harder than > 3d graphics because of concave self intersecting paths. Stroking a path can > be really hard because of thins such as tapering. > >> > >> The 3D hardware is designed to draw efficiently points, lines and > triangles. All of them are simple convex polygon. Most of the 2D vector > engines such as Cairo are software renderer, scanliners to be more > specific. The old cairo opengl backend had to tessellate the paths > >> > >> Later I am going to take a better look in Jun. And see how I can > integrate with Woden/Woden-Roassal. For what I have seen in the videos, it > seems to be using software rendering. Currently I have been working in my > internship about volumetric data visualization and the new FFI. > >> > >> 2014-12-30 11:01 GMT-03:00 kilon alios <kilon.alios(a)gmail.com>: > >> > >> Athens uses Cairo , Cairo can be used with OpenGL. You can use Cairo to > apply a 2d vector graphic as a texture to a 3d polygon. Cairo website shows > several examples of this. That means its possible to have 2d vector > graphics in 3d space as if its true 3d. > >> > >> On Tue, Dec 30, 2014 at 12:10 AM, stepharo <stepharo(a)free.fr> wrote: > >> Sven > >> > >> Jun is a 3D frameworks developed in 1998 in VisualWorks > http://aokilab.kyoto-su.ac.jp/jun/index.html > >> It was quite advanced and this is nice to get more people doing 3d in > Pharo. > >> They are using the back -end developed by ronie and JB and this is cool > >> > >> Athens is just a canvas and a oo decomposition of the canvas, brush and > strokes > >> nothing related to 3D. > >> Stef > >> > >> > >> Le 29/12/14 20:20, Sven Van Caekenberghe a Ã©crit : > >> > >> On 29 Dec 2014, at 15:36, stepharo <stepharo(a)free.fr> wrote: > >> > >> https://www.youtube.com/watch?v=sH_P5otiWJM&feature=youtu.be > >> It certainly looks nice, but what is Jun exactly ? > >> > >> > >> > >> > >> > >> > >> > >> > >> > > > > -- > _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: > Alexandre Bergel http://www.bergel.eu > ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. > > > > >

Dec. 31, 2014

Re: [Pharo-dev] GLMBrick whats next?

by Tudor Girba

Hi, Brick was born out of necessity. It is a thin layer on top of basic Morphic that is supposed to coexist with Morphic but not be bound by various problems Morphic has (such as the layout). Alex Syrel built it primarily for performance reasons and it was critical to make GTSpotter work. In the meantime, also the pager interface of GTInspector is using it as well. Currently, Brick is able to draw itself on Athens. About the relation with Bloc: we definitely do not want to end up with two solutions. Building Brick was a great learning experience. Bloc followed a rewrite from scratch approach, while Bloc is more incremental (it subclasses Morph) but it works in production. As both are able to work with Athens and both have local coordinates, I think it's a great opportunity to learn from both and find the one path that will be integrated in Pharo. Alex will be at the PharoDays and if Alain is available, he will work with Alain. Cheers, Doru On Wed, Dec 31, 2014 at 12:30 PM, stepharo <stepharo(a)free.fr> wrote: > > Le 31/12/14 11:58, Nicolai Hess a Ã©crit : > >> I took a look at GLMBrick and I am wondering what is the intent: >> >> - a temporary solution until this functions/behavior are included in >> Morphic >> > would be nice. > >> - a layer on top of morphic without the intent to do this in Morphic any >> time. >> - a temporary solution until this functions/behaviors are implemented >> with bloc >> > > I hope the third but we will need more people participating to Bloc. > > I should continue to work on the documentation.... but it takes time. > >> >> nicolai >> > > > -- www.tudorgirba.com "Every thing has its own flow"

Dec. 31, 2014

Re: [Pharo-dev] Jun4Pharo so exciting :)

by Alexandre Bergel

My email was more an encouragement than anything else :-) Alexandre > On Dec 31, 2014, at 1:06 PM, kilon alios <kilon.alios(a)gmail.com> wrote: > > not if the task is huge > > To give you an idea about the diffirence in size > > https://www.openhub.net/p/d3js > > https://www.openhub.net/p/blender > > you are a team of full time , very experienced pharo coders (correct me if i am wrong) > > me I am a part time newcomer to pharo. > > On Wed, Dec 31, 2014 at 1:59 PM, Alexandre Bergel <alexandre.bergel(a)me.com> wrote: > Well... The hard way is very gratifying. We could have worked on an integration of D3 in Pharo instead of working on Roassal :) > > Alexandre > > EnvoyÃ© de mon iPhone > > Le 31 dÃ©c. 2014 Ã 11:38, kilon alios <kilon.alios(a)gmail.com> a Ã©crit : > >> I dont doubt for a minute it will be a difficult task , this is why I chose not to do it and instead I went down the easy route of relying on existing graphics engines in my case Blender which I try to expose it to Pharo. I learned the hard way how much time one can waste doing things the hard way. >> >> On Tue, Dec 30, 2014 at 10:59 PM, Ronie Salgado <roniesalg(a)gmail.com> wrote: >> Is this a real concern ? Afterall vector data is a lot less complex than 3d geometry and CPUs nowdays are multicore. >> For really smooth and complex animations, yes it is a concern. Performance. If the objective is to draw a static shape or a slow animation, it is not a big problem. Also CPU <-> GPU data transferring is an expensive operation that has to be avoided if possible. >> >> Actually 2D vector data is more complex. 3D geometry comes already processed to be directly rendered, and it is represented by only two arrays: vertices and indices. >> >> In contrast, 2D vector data is represented by a stream of commands that have to be evaluated. >> >> BTW, we don't have support for real multithreading in Pharo, and we will not have it for a very long time. The closest thing to real multithreading that we are getting in the near term >> Don't know about the Opengl backend of Cairo. Igor also once shown me a Spec for vector graphics on OpenGL by Khronos Group. >> Well, there is OpenVG designed for mobile platform(Android and iOS). OpenVG is not supported by desktop graphic cards vendors. >> >> The closest thing we have in the desktop world is the NV_path_rendering NVIDIA only extension. At least the paper that describes this extension is really good. The bad thing is that it depends at least partially in the Loop-Blinn algorithm that is patented, if I remember right. >> >> Newest OpenGL versions also come with dynamic tesselation geometry shaders that basically increase the detail of a 3d object the closer a camera gets to it which is similar to vector graphics which is something that could also work as basic via NBOpenGL to bring Athens to 3d side completely bypassing Cairo. >> >> In first place, not all of the world have at least DX11/OpenGL 4.xx level graphic card. But, it does not matter too much because the hardware tessellation does not help you anything with the main problem. >> >> The biggest problem is that 2D vector paths can be concave, and they can have a hole . The easiest way to support it is by using the stencil buffer, and in my opinion is the method with the better results. In fact, the NV_path_rendering extension is implemented in this way, but directly in the OpenGL driver. >> >> This method renders first the tessellated path with a triangle fan, with the stencil test set to invert the stencil buffer bits. In this way, the stencil buffer holds 1 in the points that are inside of the path, and 0 in the points that are outside of the path. >> >> Then, the bounding box of the path is covered with fill color/gradient, but with the stencil test set to only pass when the stencil buffer value is 1, and to also clear the stencil buffer in the covered region during the process to allow rendering more paths elements. >> >> Each one of the changes to the way the stencil buffer is used involves a state change, which is expensive. I think this is the reason of why NVIDIA implemented their extension directly in the OpenGL. >> >> I know of these problems because I implemented once the stencil method in C++ with OpenGL. >> >> The old opengl Cairo backend worked by triangulating the paths. Triangulation of concave geometry is hard to do, and there some degenerate case in which it produces bad results. >> >> Best regards >> Ronie >> >> 2014-12-30 16:58 GMT-03:00 kilon alios <kilon.alios(a)gmail.com>: >> >> Is this a real concern ? Afterall vector data is a lot less complex than 3d geometry and CPUs nowdays are multicore. >> >> Don't know about the Opengl backend of Cairo. Igor also once shown me a Spec for vector graphics on OpenGL by Khronos Group. >> >> So there are alternatives but as always it will require someone doing the hard work to bring that functionality to Pharo. >> >> Newest OpenGL versions also come with dynamic tesselation geometry shaders that basically increase the detail of a 3d object the closer a camera gets to it which is similar to vector graphics which is something that could also work as basic via NBOpenGL to bring Athens to 3d side completely bypassing Cairo. >> >> On Tue, Dec 30, 2014 at 9:18 PM, Ronie Salgado <roniesalg(a)gmail.com> wrote: >> Athens uses Cairo , Cairo can be used with OpenGL. You can use Cairo to apply a 2d vector graphic as a texture to a 3d polygon. Cairo website shows several examples of this. That means its possible to have 2d vector graphics in 3d space as if its true 3d. >> I do not think that is going to work easily with the best performance possible. Cairo could be using OpenGL, but probably in a different OpenGL than the one that is being used for 3d graphics. >> >> In addition, the Cairo OpenGL backend is experimental (http://cairographics.org/OpenGL/) . Currently you have to render into a surface in CPU, then transfer it into GPU and then render the polygon. A naive version using the OpenGL backend is going to have GPU->CPU->GPU roundtrip >> >> If we are using this route, I think that is better to just use the current version of Athens for this. With Athens we can render into a Form, which can be used to populate a Woden/Roassal texture or transferred directly to OpenGL. This has the advantage of not having a explicit dependency in Cairo. I guess that I will make a demo of this later. It should be easy. >> >> I think that a longer term approach could be having a custom renderer, tailored for Athens using OpenGL or maybe OpenCL. >> >> 2D vector graphics are really hard. In my opinion they are harder than 3d graphics because of concave self intersecting paths. Stroking a path can be really hard because of thins such as tapering. >> >> The 3D hardware is designed to draw efficiently points, lines and triangles. All of them are simple convex polygon. Most of the 2D vector engines such as Cairo are software renderer, scanliners to be more specific. The old cairo opengl backend had to tessellate the paths >> >> Later I am going to take a better look in Jun. And see how I can integrate with Woden/Woden-Roassal. For what I have seen in the videos, it seems to be using software rendering. Currently I have been working in my internship about volumetric data visualization and the new FFI. >> >> 2014-12-30 11:01 GMT-03:00 kilon alios <kilon.alios(a)gmail.com>: >> >> Athens uses Cairo , Cairo can be used with OpenGL. You can use Cairo to apply a 2d vector graphic as a texture to a 3d polygon. Cairo website shows several examples of this. That means its possible to have 2d vector graphics in 3d space as if its true 3d. >> >> On Tue, Dec 30, 2014 at 12:10 AM, stepharo <stepharo(a)free.fr> wrote: >> Sven >> >> Jun is a 3D frameworks developed in 1998 in VisualWorks http://aokilab.kyoto-su.ac.jp/jun/index.html >> It was quite advanced and this is nice to get more people doing 3d in Pharo. >> They are using the back -end developed by ronie and JB and this is cool >> >> Athens is just a canvas and a oo decomposition of the canvas, brush and strokes >> nothing related to 3D. >> Stef >> >> >> Le 29/12/14 20:20, Sven Van Caekenberghe a Ã©crit : >> >> On 29 Dec 2014, at 15:36, stepharo <stepharo(a)free.fr> wrote: >> >> https://www.youtube.com/watch?v=sH_P5otiWJM&feature=youtu.be >> It certainly looks nice, but what is Jun exactly ? >> >> >> >> >> >> >> >> >> > -- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.

Dec. 31, 2014

Re: [Pharo-dev] Jun4Pharo so exciting :)

by kilon alios

not if the task is huge To give you an idea about the diffirence in size https://www.openhub.net/p/d3js https://www.openhub.net/p/blender you are a team of full time , very experienced pharo coders (correct me if i am wrong) me I am a part time newcomer to pharo. On Wed, Dec 31, 2014 at 1:59 PM, Alexandre Bergel <alexandre.bergel(a)me.com> wrote: > Well... The hard way is very gratifying. We could have worked on an > integration of D3 in Pharo instead of working on Roassal :) > > Alexandre > > EnvoyÃ© de mon iPhone > > Le 31 dÃ©c. 2014 Ã 11:38, kilon alios <kilon.alios(a)gmail.com> a Ã©crit : > > I dont doubt for a minute it will be a difficult task , this is why I > chose not to do it and instead I went down the easy route of relying on > existing graphics engines in my case Blender which I try to expose it to > Pharo. I learned the hard way how much time one can waste doing things the > hard way. > > On Tue, Dec 30, 2014 at 10:59 PM, Ronie Salgado <roniesalg(a)gmail.com> > wrote: > >> Is this a real concern ? Afterall vector data is a lot less complex than >>> 3d geometry and CPUs nowdays are multicore. >> >> For really smooth and complex animations, yes it is a concern. >> Performance. If the objective is to draw a static shape or a slow >> animation, it is not a big problem. Also CPU <-> GPU data transferring is >> an expensive operation that has to be avoided if possible. >> >> Actually 2D vector data is more complex. 3D geometry comes already >> processed to be directly rendered, and it is represented by only two >> arrays: vertices and indices. >> >> In contrast, 2D vector data is represented by a stream of commands that >> have to be evaluated. >> >> BTW, we don't have support for real multithreading in Pharo, and we will >> not have it for a very long time. The closest thing to real multithreading >> that we are getting in the near term >> >>> Don't know about the Opengl backend of Cairo. Igor also once shown me a >>> Spec for vector graphics on OpenGL by Khronos Group. >>> >> Well, there is OpenVG designed for mobile platform(Android and iOS). >> OpenVG is not supported by desktop graphic cards vendors. >> >> The closest thing we have in the desktop world is the NV_path_rendering >> NVIDIA only extension. At least the paper that describes this extension is >> really good. The bad thing is that it depends at least partially in the >> Loop-Blinn algorithm that is patented, if I remember right. >> >> Newest OpenGL versions also come with dynamic tesselation geometry >>> shaders that basically increase the detail of a 3d object the closer a >>> camera gets to it which is similar to vector graphics which is something >>> that could also work as basic via NBOpenGL to bring Athens to 3d side >>> completely bypassing Cairo. >>> >> >> In first place, not all of the world have at least DX11/OpenGL 4.xx level >> graphic card. But, it does not matter too much because the hardware >> tessellation does not help you anything with the main problem. >> >> The biggest problem is that 2D vector paths can be concave, and they can >> have a hole . The easiest way to support it is by using the stencil buffer, >> and in my opinion is the method with the better results. In fact, the >> NV_path_rendering extension is implemented in this way, but directly in the >> OpenGL driver. >> >> This method renders first the tessellated path with a triangle fan, with >> the stencil test set to invert the stencil buffer bits. In this way, the >> stencil buffer holds 1 in the points that are inside of the path, and 0 in >> the points that are outside of the path. >> >> Then, the bounding box of the path is covered with fill color/gradient, >> but with the stencil test set to only pass when the stencil buffer value is >> 1, and to also clear the stencil buffer in the covered region during the >> process to allow rendering more paths elements. >> >> Each one of the changes to the way the stencil buffer is used involves a >> state change, which is expensive. I think this is the reason of why NVIDIA >> implemented their extension directly in the OpenGL. >> >> I know of these problems because I implemented once the stencil method in >> C++ with OpenGL. >> >> The old opengl Cairo backend worked by triangulating the paths. >> Triangulation of concave geometry is hard to do, and there some degenerate >> case in which it produces bad results. >> >> Best regards >> Ronie >> >> 2014-12-30 16:58 GMT-03:00 kilon alios <kilon.alios(a)gmail.com>: >> >> Is this a real concern ? Afterall vector data is a lot less complex than >>> 3d geometry and CPUs nowdays are multicore. >>> >>> Don't know about the Opengl backend of Cairo. Igor also once shown me a >>> Spec for vector graphics on OpenGL by Khronos Group. >>> >>> So there are alternatives but as always it will require someone doing >>> the hard work to bring that functionality to Pharo. >>> >>> Newest OpenGL versions also come with dynamic tesselation geometry >>> shaders that basically increase the detail of a 3d object the closer a >>> camera gets to it which is similar to vector graphics which is something >>> that could also work as basic via NBOpenGL to bring Athens to 3d side >>> completely bypassing Cairo. >>> >>> On Tue, Dec 30, 2014 at 9:18 PM, Ronie Salgado <roniesalg(a)gmail.com> >>> wrote: >>> >>>> Athens uses Cairo , Cairo can be used with OpenGL. You can use Cairo to >>>>> apply a 2d vector graphic as a texture to a 3d polygon. Cairo website shows >>>>> several examples of this. That means its possible to have 2d vector >>>>> graphics in 3d space as if its true 3d. >>>>> >>>> I do not think that is going to work easily with the best performance >>>> possible. Cairo could be using OpenGL, but probably in a different OpenGL >>>> than the one that is being used for 3d graphics. >>>> >>>> In addition, the Cairo OpenGL backend is experimental ( >>>> http://cairographics.org/OpenGL/) . Currently you have to render into >>>> a surface in CPU, then transfer it into GPU and then render the polygon. A >>>> naive version using the OpenGL backend is going to have GPU->CPU->GPU >>>> roundtrip >>>> >>>> If we are using this route, I think that is better to just use the >>>> current version of Athens for this. With Athens we can render into a Form, >>>> which can be used to populate a Woden/Roassal texture or transferred >>>> directly to OpenGL. This has the advantage of not having a explicit >>>> dependency in Cairo. I guess that I will make a demo of this later. It >>>> should be easy. >>>> >>>> I think that a longer term approach could be having a custom renderer, >>>> tailored for Athens using OpenGL or maybe OpenCL. >>>> >>>> 2D vector graphics are really hard. In my opinion they are harder than >>>> 3d graphics because of concave self intersecting paths. Stroking a path can >>>> be really hard because of thins such as tapering. >>>> >>>> The 3D hardware is designed to draw efficiently points, lines and >>>> triangles. All of them are simple convex polygon. Most of the 2D vector >>>> engines such as Cairo are software renderer, scanliners to be more >>>> specific. The old cairo opengl backend had to tessellate the paths >>>> >>>> Later I am going to take a better look in Jun. And see how I can >>>> integrate with Woden/Woden-Roassal. For what I have seen in the videos, it >>>> seems to be using software rendering. Currently I have been working in my >>>> internship about volumetric data visualization and the new FFI. >>>> >>>> 2014-12-30 11:01 GMT-03:00 kilon alios <kilon.alios(a)gmail.com>: >>>> >>>> Athens uses Cairo , Cairo can be used with OpenGL. You can use Cairo to >>>>> apply a 2d vector graphic as a texture to a 3d polygon. Cairo website shows >>>>> several examples of this. That means its possible to have 2d vector >>>>> graphics in 3d space as if its true 3d. >>>>> >>>>> On Tue, Dec 30, 2014 at 12:10 AM, stepharo <stepharo(a)free.fr> wrote: >>>>> >>>>>> Sven >>>>>> >>>>>> Jun is a 3D frameworks developed in 1998 in VisualWorks >>>>>> http://aokilab.kyoto-su.ac.jp/jun/index.html >>>>>> It was quite advanced and this is nice to get more people doing 3d in >>>>>> Pharo. >>>>>> They are using the back -end developed by ronie and JB and this is >>>>>> cool >>>>>> >>>>>> Athens is just a canvas and a oo decomposition of the canvas, brush >>>>>> and strokes >>>>>> nothing related to 3D. >>>>>> Stef >>>>>> >>>>>> >>>>>> Le 29/12/14 20:20, Sven Van Caekenberghe a Ã©crit : >>>>>> >>>>>> On 29 Dec 2014, at 15:36, stepharo <stepharo(a)free.fr> wrote: >>>>>>>> >>>>>>>> https://www.youtube.com/watch?v=sH_P5otiWJM&feature=youtu.be >>>>>>>> >>>>>>> It certainly looks nice, but what is Jun exactly ? >>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>>> >>>>> >>>> >>> >> >

Dec. 31, 2014

Re: [Pharo-dev] Jun4Pharo so exciting :)

by Alexandre Bergel

Well... The hard way is very gratifying. We could have worked on an integration of D3 in Pharo instead of working on Roassal :) Alexandre EnvoyÃ© de mon iPhone > Le 31 dÃ©c. 2014 Ã 11:38, kilon alios <kilon.alios(a)gmail.com> a Ã©crit : > > I dont doubt for a minute it will be a difficult task , this is why I chose not to do it and instead I went down the easy route of relying on existing graphics engines in my case Blender which I try to expose it to Pharo. I learned the hard way how much time one can waste doing things the hard way. > > On Tue, Dec 30, 2014 at 10:59 PM, Ronie Salgado <roniesalg(a)gmail.com> wrote: >>> Is this a real concern ? Afterall vector data is a lot less complex than 3d geometry and CPUs nowdays are multicore. >> >> For really smooth and complex animations, yes it is a concern. Performance. If the objective is to draw a static shape or a slow animation, it is not a big problem. Also CPU <-> GPU data transferring is an expensive operation that has to be avoided if possible. >> >> Actually 2D vector data is more complex. 3D geometry comes already processed to be directly rendered, and it is represented by only two arrays: vertices and indices. >> >> In contrast, 2D vector data is represented by a stream of commands that have to be evaluated. >> >> BTW, we don't have support for real multithreading in Pharo, and we will not have it for a very long time. The closest thing to real multithreading that we are getting in the near term >>> Don't know about the Opengl backend of Cairo. Igor also once shown me a Spec for vector graphics on OpenGL by Khronos Group. >> >> Well, there is OpenVG designed for mobile platform(Android and iOS). OpenVG is not supported by desktop graphic cards vendors. >> >> The closest thing we have in the desktop world is the NV_path_rendering NVIDIA only extension. At least the paper that describes this extension is really good. The bad thing is that it depends at least partially in the Loop-Blinn algorithm that is patented, if I remember right. >> >>> Newest OpenGL versions also come with dynamic tesselation geometry shaders that basically increase the detail of a 3d object the closer a camera gets to it which is similar to vector graphics which is something that could also work as basic via NBOpenGL to bring Athens to 3d side completely bypassing Cairo. >> >> >> In first place, not all of the world have at least DX11/OpenGL 4.xx level graphic card. But, it does not matter too much because the hardware tessellation does not help you anything with the main problem. >> >> The biggest problem is that 2D vector paths can be concave, and they can have a hole . The easiest way to support it is by using the stencil buffer, and in my opinion is the method with the better results. In fact, the NV_path_rendering extension is implemented in this way, but directly in the OpenGL driver. >> >> This method renders first the tessellated path with a triangle fan, with the stencil test set to invert the stencil buffer bits. In this way, the stencil buffer holds 1 in the points that are inside of the path, and 0 in the points that are outside of the path. >> >> Then, the bounding box of the path is covered with fill color/gradient, but with the stencil test set to only pass when the stencil buffer value is 1, and to also clear the stencil buffer in the covered region during the process to allow rendering more paths elements. >> >> Each one of the changes to the way the stencil buffer is used involves a state change, which is expensive. I think this is the reason of why NVIDIA implemented their extension directly in the OpenGL. >> >> I know of these problems because I implemented once the stencil method in C++ with OpenGL. >> >> The old opengl Cairo backend worked by triangulating the paths. Triangulation of concave geometry is hard to do, and there some degenerate case in which it produces bad results. >> >> Best regards >> Ronie >> >> 2014-12-30 16:58 GMT-03:00 kilon alios <kilon.alios(a)gmail.com>: >> >>> Is this a real concern ? Afterall vector data is a lot less complex than 3d geometry and CPUs nowdays are multicore. >>> >>> Don't know about the Opengl backend of Cairo. Igor also once shown me a Spec for vector graphics on OpenGL by Khronos Group. >>> >>> So there are alternatives but as always it will require someone doing the hard work to bring that functionality to Pharo. >>> >>> Newest OpenGL versions also come with dynamic tesselation geometry shaders that basically increase the detail of a 3d object the closer a camera gets to it which is similar to vector graphics which is something that could also work as basic via NBOpenGL to bring Athens to 3d side completely bypassing Cairo. >>> >>> On Tue, Dec 30, 2014 at 9:18 PM, Ronie Salgado <roniesalg(a)gmail.com> wrote: >>>>> Athens uses Cairo , Cairo can be used with OpenGL. You can use Cairo to apply a 2d vector graphic as a texture to a 3d polygon. Cairo website shows several examples of this. That means its possible to have 2d vector graphics in 3d space as if its true 3d. >>>> >>>> I do not think that is going to work easily with the best performance possible. Cairo could be using OpenGL, but probably in a different OpenGL than the one that is being used for 3d graphics. >>>> >>>> In addition, the Cairo OpenGL backend is experimental (http://cairographics.org/OpenGL/) . Currently you have to render into a surface in CPU, then transfer it into GPU and then render the polygon. A naive version using the OpenGL backend is going to have GPU->CPU->GPU roundtrip >>>> >>>> If we are using this route, I think that is better to just use the current version of Athens for this. With Athens we can render into a Form, which can be used to populate a Woden/Roassal texture or transferred directly to OpenGL. This has the advantage of not having a explicit dependency in Cairo. I guess that I will make a demo of this later. It should be easy. >>>> >>>> I think that a longer term approach could be having a custom renderer, tailored for Athens using OpenGL or maybe OpenCL. >>>> >>>> 2D vector graphics are really hard. In my opinion they are harder than 3d graphics because of concave self intersecting paths. Stroking a path can be really hard because of thins such as tapering. >>>> >>>> The 3D hardware is designed to draw efficiently points, lines and triangles. All of them are simple convex polygon. Most of the 2D vector engines such as Cairo are software renderer, scanliners to be more specific. The old cairo opengl backend had to tessellate the paths >>>> >>>> Later I am going to take a better look in Jun. And see how I can integrate with Woden/Woden-Roassal. For what I have seen in the videos, it seems to be using software rendering. Currently I have been working in my internship about volumetric data visualization and the new FFI. >>>> >>>> 2014-12-30 11:01 GMT-03:00 kilon alios <kilon.alios(a)gmail.com>: >>>> >>>>> Athens uses Cairo , Cairo can be used with OpenGL. You can use Cairo to apply a 2d vector graphic as a texture to a 3d polygon. Cairo website shows several examples of this. That means its possible to have 2d vector graphics in 3d space as if its true 3d. >>>>> >>>>>> On Tue, Dec 30, 2014 at 12:10 AM, stepharo <stepharo(a)free.fr> wrote: >>>>>> Sven >>>>>> >>>>>> Jun is a 3D frameworks developed in 1998 in VisualWorks http://aokilab.kyoto-su.ac.jp/jun/index.html >>>>>> It was quite advanced and this is nice to get more people doing 3d in Pharo. >>>>>> They are using the back -end developed by ronie and JB and this is cool >>>>>> >>>>>> Athens is just a canvas and a oo decomposition of the canvas, brush and strokes >>>>>> nothing related to 3D. >>>>>> Stef >>>>>> >>>>>> >>>>>> Le 29/12/14 20:20, Sven Van Caekenberghe a Ã©crit : >>>>>> >>>>>>>> On 29 Dec 2014, at 15:36, stepharo <stepharo(a)free.fr> wrote: >>>>>>>> >>>>>>>> https://www.youtube.com/watch?v=sH_P5otiWJM&feature=youtu.be >>>>>>> It certainly looks nice, but what is Jun exactly ? >

Dec. 31, 2014

Re: [Pharo-dev] GLMBrick whats next?

by stepharo

Le 31/12/14 11:58, Nicolai Hess a Ã©crit : > I took a look at GLMBrick and I am wondering what is the intent: > > - a temporary solution until this functions/behavior are included in > Morphic would be nice. > - a layer on top of morphic without the intent to do this in Morphic > any time. > - a temporary solution until this functions/behaviors are implemented > with bloc I hope the third but we will need more people participating to Bloc. I should continue to work on the documentation.... but it takes time. > > nicolai

Dec. 31, 2014

Re: [Pharo-dev] archives?

by stepharo

Thanks sven Stef Le 31/12/14 11:20, Sven Van Caekenberghe a Ã©crit : > Also a good morning, not yet fully awake ? > > ;-) > > http://pharo.org/community > http://forum.world.st/Pharo-Smalltalk-Developers-f1294837.html > http://lists.pharo.org/pipermail/pharo-dev_lists.pharo.org/ > >> On 31 Dec 2014, at 11:13, stepharo <stepharo(a)free.fr> wrote: >> >> is this mailing-list archived? >> Because I would like to browse it >> Stef >> > >

Dec. 31, 2014

GLMBrick whats next?

by Nicolai Hess

I took a look at GLMBrick and I am wondering what is the intent: - a temporary solution until this functions/behavior are included in Morphic - a layer on top of morphic without the intent to do this in Morphic any time. - a temporary solution until this functions/behaviors are implemented with bloc nicolai

Dec. 31, 2014