Transparency/AlphaBlend Issue

Scripting Issues
1

I am trying to create a table top which has a glass like transparent surface. The model was in blender, exported as gltf and the exported gltf is rendered fine in gltf-viewer as well as in Win10 3D viewer. However, in a panda3D script the surface is never visible, possibly being fully transparent/never rendered. This maybe related to the “Transparency and Blending” issues in the manual, but I couldn’t fix with the suggestions there on transparency attribs and other attempts such as disabling auto shader. Basically there is a material attached a geometry with an alpha color.

I’ve attached a small python file to simulate the issue and the gltf file.

Python file
Gltf

Here is the relevant gltf material section that has the alpha blending mode.

{
            "alphaMode" : "BLEND",
            "doubleSided" : true,
            "name" : "table_top",
            "pbrMetallicRoughness" : {
                "baseColorFactor" : [
                    0.8000000715255737,
                    0.7112227082252502,
                    0.7378523349761963,
                    0.43299999833106995
                ],
                "roughnessFactor" : 0.15199999511241913
            }
        }

And the code snippet:

super().__init__()
gltf.patch_loader(self.loader)

model = loader.load_model(r'glass1.gltf')
model.reparent_to(self.render)

alight = AmbientLight('alight')
alight.setColor((1, 1, 1, 1))
alnp = render.attachNewNode(alight)
self.render.setLight(alnp)

self.cam.set_y(-50)

self.render.setShaderAuto()

Appreciate your suggestions.

2

Do your materials rely on PBR elements? If so, you may want to try activating “simplepbr” (see here).

(Or otherwise creating your own PBR shaders, of course.)