Le 30/12/14 20:18, Ronie Salgado a écrit :
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.
this would be nice :)
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 <[email protected]
<mailto:[email protected]>>:
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 <[email protected]
<mailto:[email protected]>> 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 écrit :
On 29 Dec 2014, at 15:36, stepharo <[email protected]
<mailto:[email protected]>> wrote:
https://www.youtube.com/watch?v=sH_P5otiWJM&feature=youtu.be
It certainly looks nice, but what is Jun exactly ?
