how to make a visual model(OglModel) transparent?

[SalemTree]

Hi, I'm trying to simulate a cornea in SOFA, I have the obj and msh files prepared, but is there anyway to make the visual model transparent like a real cornea(like glass)? I tried to add texture in the oglmodel but it doent look like glass(of course)

[hugtalbot]

Hi @SalemTree

Thanks for your question!
For such a rendering topic, let me poke @fredroy

[fredroy]

hello @SalemTree

You need to have the material alpha component to less than 1.0 (or less than 255 if the color is defined on 8bits).
And if you have a mtl file, the transparency is set with the "d" field.

Note that this is using really basic transparency of OpenGL, and not suitable for what you are trying to achieve (glass-type translucy).
You may have to implement some shaders for this, but SOFA is not really suitable for "advanced" rendering for now.
There are some plans to possibly get it in the future (using other game engine) but for now, I would advise to design your physical simulation with runSofa and then link it with an other tool/program/framework to get advanced rendering (unity, blender,...)

[SalemTree]

hello @fredroy
Thank you for the clarification. I'll try tweak the material alpha component and check how it looks.
There is a eye surgery simulator called HelpMeSee which is claimed to be developed with Sofa.

This kind of rendering would be enough for me. Do I still have to link my sofa simulation to external program like you explained to achieve this kind of effect?

[fredroy]

I dont have all the technical details about this product (MSICS) but I think there are using an external rendering engine made by the company SenseGraphics (which is now part of the company Surgical Science https://surgicalscience.com/sense-graphics/ ).
You may contact them if you want more info about their rendering engine.