By: Simon Danisch

Re-posted from: https://randomphantasies.wordpress.com/2014/07/25/update-gsoc/

First of all, a few things actually got less comfortable.

That’s because I stopped acting like I have a scene Graph and now fully expose the render loop. I think this offers greater flexibility for early adopters.

That means instead of display I rather expose the function toopengl, which I intend to use to build up the scene graph later on.

Also I’m not fully happy with the API, but that is to be expected, as I haven’t figured out the scene graph and its interaction with React yet.

BUT, I have most of the pieces together now, to do the basic render operations, which you would expect from a 3D plotting package and most of the render attributes can be be time changing signals, which enables nice animation capabilities.

You can find examples with a few comments in GLPlot/examples

By the way, all shaders are interactive now by default.

That means you can just run the example, open a shader in a text editor, edit something, save -> et voilà =)

For example if you run example/surface.jl, GLPlot/src/shader/phongblinn.frag might be interesting.

Or volume.jl and GLPlot/src/shader/iso.frag.

 

Here are some screen-shots/videos:

Going through some iso-values:

Tiny cubes animated with different attributes:

2D geometry projected on z-value grid:

Same without seams (Surface Plot):

Iso surface:

Best,

Simon

By: Simon Danisch

Re-posted from: https://randomphantasies.wordpress.com/2014/06/25/update/

All updates are not on github yet, as I still need to put some work into this to expose it within an API.

API:

What I want to implement:

gldisplay(img::Union(Image{Real, Union(1,2,3)}, Texture))

Shows an Image as either a histogram for 1D image, Picture for 2D Image, volume rendering for 3D Picture

gldisplay(x::Range, y::Range,

attributes::Union(Image{Real,2},Texture, Array{Real, 2}…;

primitive=Triangle/Cube/Mesh)

This can be used for any grid based surface/histogram/bar graph rendering,but can also be extended to be used as a particle system.creates a grid x*y, where for every tuple (x,y) attributes will be read from the attributes at position (x,y), which will be applied to the primitive for every position in x*y.

The last API is a little bit difficult to implement, if I want to make it fully transparent and customizable for the user, as they are dependent on some shader.

But for now, I can have some predefined attributes like width, height, xpos, ypos, color and only expose them to the user.

Example renders are under the point Surfaces.

If  we advance the OpenCL/OpenGL interoperability, the Texture in attributes and image, can also be an OpenCL Image/Buffer, which would make it possible to render any results from OpenCL easily to the screen.

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Volume:

Added:

• more reliable and faster rendering
• correct voxel spacing
• maybe skewed voxels (still needs to be tested)

To be implemented

• Lighting
• Slicing plane
• Transfer function with 1D texture

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Surface:

Instanced geometry (in this case a cube) rendering with arrays for attributes like position, height, color:

The data is fully controllable with React.jl:

https://www.youtube.com/watch?v=nJdGHVY2b2g&feature=youtu.be

This also works for surfaces and 3D textures, but is not implemented yet.

This approach only needs to upload one third of the data compared to my previous approach, but as a downside requires OpenGL 3.3.

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Camera:

The camera is still horrible, but at least works now completely with React.

To be fixed:

• Glitches, which come from previous values, because signal doesn’t start from zero for a new drag operation.
• Camera flips, as I don’t calculate the rotation correctly

To be implemented:

• panning
• pick rotation axis

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3D Picking:

I started with the groundwork for a general 3d picking framework, which will allow for some awesome selection API together with React.

This will allow for very precise information for every mouse position, like distance of object, group it belongs to, coordinates in some custom coordinate space.

Like that, precise Mesh/Particle/Volume/Text/UI-Element selection and editable object pivots just got one step closer!