[x3d-public] Blender X3D exporter: what to do, how to do it

Fri Jul 2 05:43:26 PDT 2021

Can it do a transparent object which gets a lot of surface color from 
the surrounding cubemap, yet also refracts?

Like this fragment shader (I can provide a sample vertex shader if 
you're interested):

I think what I may actually be searching for is chromatic dispersion.   
Sorry for any confusion.  I guess I should read the code...

On 7/2/21 7:29 AM, Michalis Kamburelis wrote:
> In Castle Game Engine, the way to code simple chromatic aberration
> effect is using "screen effects",
> https://castle-engine.io/x3d_extensions_screen_effects.php . We used
> it in "Escape from the Universe",
> https://www.nintendo.com/games/detail/escape-from-the-universe-switch/
> .
>
> Regards,
> Michalis
>
> pt., 2 lip 2021 o 13:10 John Carlson <yottzumm at gmail.com> napisał(a):
>> Thanks for your help, Michalis, unfortunately I am buried getting my examples working again with X3DJSAIL, X3DOM, and X_ITE,  even my XML urls are broken.   Staying on the bleeding edge of other’s work means you have to play catch up.
>>
>> I have also been updating JSON schema for synonyms, working on X3DJSAIL, and making sure view3dscene works in X3D-Edit on Linux.
>>
>> I am wanting to get an X3D player to do what I call chromatic aberration: rainbow effects like soap bubbles and CDs.   Would you like to collaborate?   I need someone to help design the nodes and help with implementation.   There’s a glTF extension or two which may be somewhat applicable, but probably still incomplete.   I also have shaders written for PlayCanvas which might help bootstrap…see my flowers.html
>>
>> I’ve seen others tackle rainbow effects on CDs, but I’ve lost track of the site…
>>
>> If there is chromatic aberration in Blender, I can help getting it exported.
>>
>> John
>>
>> On Fri, Jul 2, 2021 at 5:42 AM Michalis Kamburelis <michalis.kambi at gmail.com> wrote:
>>> (sorry for delay in answering -- I was on short vacation)
>>>
>>> John -- to get the image (texture for the "base" material property) in
>>> new Blender, you need to get the texture from the PBR nodes.
>>>
>>> You can see e.g. how glTF exporter gets the texture (source code
>>> https://github.com/KhronosGroup/glTF-Blender-IO , user docs
>>> https://docs.blender.org/manual/en/dev/addons/import_export/scene_gltf2.html
>>> ). Basically you have to access the "node tree" of Blender material
>>> like "material.node_tree.nodes["Principled BSDF"].inputs[0]" and find
>>> the node with type "ShaderNodeTexImage" that is connected to it. This
>>> will have an "image" field that contains the Blender image.
>>>
>>> You can/should read Blender API docs in
>>> https://docs.blender.org/api/current/  to know the necessary API. The
>>> names are also visible as Blender hints (on mouse over) and can be
>>> even copied using context menu. Be sure to enable "Developer Extras"
>>> and "Python Tooltips" in Blender preferences, see screenshots.
>>>
>>> Regards,
>>> Michalis
>>>
>>> czw., 24 cze 2021 o 23:15 John Carlson <yottzumm at gmail.com> napisał(a):
>>>> More info, feel free to append to Blender ticket as you see fit. I clicked on "Image" between the 2 main panels, and set the image to "tuna.png"  it looked like the image was applied (yay), but tuna.png did not appear in the .x3d, and the output was still "Image None" at line 654. And output x3d did not show the texture in FreeWRL or view3dscene.
>>>>
>>>> An investigation of the Blender file:
>>>>
>>>> $ strings x3d_texture_2.83.blend|grep png
>>>> Untitled.png
>>>> //tuna.png
>>>> Desktop/Untitled.png
>>>>
>>>> So there's still some places to cover.  I do not yet know how to make image non-None. I did some settings in base color to tuna (not tuna.png).  It will take some time to figure out all the windows/panels.  There are a lot of choices in Blender.   It would probably be worth it to take some classes!
>>>>
>>>> Note: This is the only place in the export code that <Appearance> appears, so this pretty much has to be the code, and we just need to figure out how to set image variable properly in the preceding code.
>>>>
>>>> If a python programmer could translate this line (614? of /usr/share/blender/scripts/addons/io_scene_x3d/export_x3d.py ) to English, it would help!
>>>>
>>>> for (material_index, image), polygons_group in polygons_groups.items():
>>>>
>>>> I think this is where the image variable comes from.
>>>>
>>>> John
>>>>
>>>> On 6/24/21 3:08 PM, John Carlson wrote:
>>>>
>>>> I added these lines to the Blender X3D exporter, at line 654
>>>>
>>>>                     print("Image", image)
>>>>                      print("Use H3D", use_h3d)
>>>>
>>>>
>>>> Here is the output:
>>>>
>>>> Image None
>>>> Use H3D False
>>>>
>>>> So...the image is not set?  Let's do some snooping:
>>>>
>>>> coderextreme at coderextreme-Kubuntu20:~/Downloads$ strings x3d_texture_2.82.blend |grep png
>>>> Untitled.png
>>>> //Untitled.png
>>>> Desktop/Untitled.png
>>>> coderextreme at coderextreme-Kubuntu20:~/Downloads$ strings x3d_texture_2.79.blend |grep png
>>>> Untitled.png
>>>> //Untitled.png
>>>> Desktop/Untitled.png
>>>>
>>>> I don't have these pngs.
>>>>
>>>> I will look and see how to set the png for the texture, meanwhile, I don't think that the png exists, therefore, image is None, and the ImageTexture and TextureTransform don't print!
>>>>
>>>> I'll get back to you!
>>>>
>>>> John
>>>>
>>>> On 6/24/21 1:34 PM, John Carlson wrote:
>>>>
>>>> Note:
>>>>
>>>> https://developer.blender.org/T66534
>>>>
>>>> Has some sample files to start with.
>>>>
>>>> On 6/22/21 7:48 AM, Michalis Kamburelis wrote:
>>>>
>>>> I wrote a document outlining my Blender->X3D exporter wishlist, and
>>>> how to submit patches to Blender:
>>>>
>>>> https://docs.google.com/document/d/1ad5XsU43gQGxqC7ehSBr21mdX2dQjKZCSXUQtvRwTHw/edit?usp=sharing
>>>>
>>>> Please feel free to distribute it to whoever is interested. Comments welcome :)
>>>>
>>>> Regards,
>>>> Michalis
>>>>
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