PNG Import Texture Transparency Complicated Problem

[tysongersh]

I just retried after exploding all groups in the model and tried the exporter again and got the following message (I think it’s the same one as before)

[TIG]

Get in touch directly with this Extension’s author.

We cannot understand how it processes the model because the chosen file encryption of RBE.

[colin]

You could try the extension on a simpler model, just to see what it normally would do.

[tysongersh]

I just left the following as a Review. I couldnt figure out how to message the author (Centaur) directly, but it seems like other people were posting problems and Centaur was addressing them as replies.

[tysongersh]

HOLY ■■■■! wow. it does work. SO COOL THANK YOU! If this could add just a few features to make it look prettier, this would be a complete replacement for SketchFab!

I’m surprised that the file type isnt supported by the SketchUp forums to post in threads, but still cool

[Centaur]

I’ve uploaded version 1.2.2 to address the issue in the exporter. Should be available shortly, but for anyone else reading this thread, don’t explode the model. The exporter was crashing when it encountered nil material within un-grouped geometry.

Also, I’m wondering if instead of modelling all the bricks, a normal-map texture could be applied?
That can’t be done within Sketchup, but you could manually edit the glTF file to insert it. But then, how are you uploading the file to SketchFab?

[tysongersh]

Thank you for following up!

Oh, wow this worked out really well (it loaded crazy fast), though it included some geography/location data that I had deleted?

I guess I deleted the map layer visually, but retained the location data? Tried it again after clearing the location data and it was all good (though, it would be cool if there was a way to keep location data in the model and still be able to export it)

I’m not sure what a normal-map texture is. Is that the same as a typical texture?
My issue is that the the mural on the building only exists on the brick faces themselves and not the mortar, which is recessed .5" in .5" gaps between the bricks, so in an effort to mirror the real world situation as best as possible, I figured it would be as best to detailed and specific.

Today is the first time that I’ve worked with glTF files (as least to my knowledge). I’m not even sure what platform I’d use to edit them, but I could try?

To get the files into SketchFab I use this SketchFab importer plugin

It’s actually pretty good, though it crashes if you try and upload anything with a dynamic component in it. The only real shortcoming is that you can’t update models with it, so if you make a change to a model you have to upload it as a completely unique file.

[Centaur]

I’m not sure but maybe the background location data is on another layer? I’m not taking layers into account during export. Probably something I need to fix.

Here is an example of normal-mapping (or ‘bump’ mapping).

Both models are a square metre textured with the same brick texture, exported from Sketchup to glTF, but in the first model there is an additional normal map which I added manually by editing the .gltf file in a text editor.

You will note the additional depth that the normal map adds, whereas the second model is ‘flatter’.

While you could apply the mortar lines directly to your texture, it wouldn’t look as good without a normal map.

Unfortunately, Sketchup doesn’t support normal maps - it would require an additional texture uploaded per material, but that isn’t hard to do - I guess the team at Trimble are more focused on architectural modeling rather than game modeling where normal maps are more common.

[colin]

I didn’t know the difference between Normal and Bump. Here’s an interesting article that explains it:

https://www.pluralsight.com/blog/film-games/bump-normal-and-displacement-maps

[Centaur]

The normal map I used for the above model is this one…

Normal maps are always bluish in overall colour because they represent x,y,z in the r,g,b values, and normals default to 0,0,1. They add to the ‘normal’ (direction that face is facing) and are typically, but not always, mapped using the same UV coordinates as the diffuse texture.

[colin]

If I understand it right then, a normal map is like having three bump maps, whereas a regular bump map is just a height map really. That is, only the z (or is it w for textures?) direction.

[Centaur]

It is not quite like having three bump maps, as the normal is a direction. The rgb in the normal map translates to xyz (in a range of -1 to 1 for each component), and this is multiplied by the actual surface normal of the face (actually the fragment being rendered, which is an interpolated value when the face has smooth edges).
This allows lighting calculations to determine if the fragment has more or less lighting at that pixel, based on the calculated normal. It gives the overall model much greater detail without requiring a high polygon count.

[tysongersh]

This seems like a great solution for a lot of reasons (i.e. reducing file size and model performance in viewers), but I’m worried that it would compromise the accuracy of the model. Part of the goal of this particular model is to be super super details/accurate in terms of it’s parts so that it can be used in some sort of building information management platform (I’d like to figure out how to do this in SketchUp) that would provide real time building performance data (i.e. a thermal imaging filter that showed temp distribution & heat loss, electrical performance via some sort of graphs or maybe even an animated wiring diagram, water/rainwater/gray water facility management, etc.).

This is a super lofty goal that will be built incrementally. I am really happy that you shared that info about the different types of maps though - I learned a lot from it.

With all that in mind, does anyone have any suggestions on how I can solve the transparency issue that I’m still having? lol

[Centaur]

The best solution would be Colin’s initial suggestion to replace the transparent parts of the image with the brick colour. I understand that you would prefer to keep the unpainted bricks their own colour, and to do that you would need to select and paint them with another material.

For reflectivity and roughness, you would need to generate specular and/or metallic/roughness maps for the brick colour in the mural vs the paint itself. But that is a whole other topic and another thing that Sketchup doesn’t provide natively.

[whiterabbitdesigncompany]

I’d sent you an earlier post that demonstrated a solution as you wanted…only brick “faces” painted, grout color and sides of bricks unaltered. It basically had the brick color filling the transparent areas and then only projected onto the faces of the brick (not the whole model which would affect sides of bricks and grout.)