Problem opening a Zephyr mesh in Meshlab

[Shopgeezer]

Hi to the group. I am trying Zephyr free. I took 50 photos of my subject, 43 of which were accepted by Zephyr. I followed the online Workflow tutorial video as I created my own mesh. I did exactly what the presenter did in the video. I managed to get a good looking textured mesh made in Zephyr. In the video the presenter then exports the mesh as a .obj file and opens it in MeshLab. His mesh in MeshLab looks just like it did in Zephyr, same colours, textures etc. I exported my mesh as an .obj file but when I opened it in MeshLab I got the following error:

" Some materials definitions were not found. A default white material is used where no material was available".

My object in MeshLab looks like a blob of clay. All of it seems to be the "white material". So why did the presenter's mesh in the video look fine in MeshLab, and my mesh file looks like a pile of whipped cream? What are the materials definitions that MeshLab is looking for? Is this a problem in the export function in Zephyr? I followed all the options that the presenter in the video used.

[cam3d]

Hey Shopgeezer, in Zephyr you don't have the 3D light turned on, you're only seeing the flat un-illuminated texture map - To see the actual 3D geometry in Zephyr you need to click on the lightbulb icon in the tool-bar.

The reason your model is a bit blobby is that the surface properties of your subject are relatively feature poor, not providing a lot of information to Zephyr to reconstruct with, which requires you to work harder to get compatible results to reality. More photos which are as sharp as possible and with a higher resolution and studio lighting would improve the surface reconstruction.

Now I think the reason your material to obj link is broken is because of the spacing in your file naming. Try replacing the spaces with _underscores_ or format your naming inCamelCase. This should fix your broken texture issue. I've never actually encountered that before today, but I did a test myself and the spacing broke my test file - I assume it's an external issue and not something which can be accounted for on the Zephyr side of things Andrea Alessi ??



?

[Andrea Alessi]

Hi Shopgeezer,

as Cam mentioned the problem is the space in your filename (China Cat Green.obj) which is not supported by the wavefront format.

While we could force a file rename, e.g. an underscore, I think we do not as some workflows actually rely on the broken filename to be exported as it is. In fact, other software such as blender have the same behaviour and will export the broken mtl file as zephyr does.

I will raise a ticket in our internal tracker however, it is probably a good idea to at least warn the user.

So to fix your issue, simply select a name in export that has no spaces, e.g. china_cat_green.obj - textures and mtl file will be generated accordingly.

[Shopgeezer]

Whoo hoo! Putting in the underscores worked. The file now displays perfectly in MeshLab. I guess we get lazy these days. Time was when all files had to have underscores on spaces. The later versions of Windows, and especially Office, no longer require this. Good to mention that to users.

Turning on the light bulb icon in Zephyr revealed all the lumps and bumps in the surface of the cat. MeshLab shows these as well. The free version of Zephyr only allows 50 photos. I am going to buy the 3DF Zephyr Lite version since I think the Zephyr does everything I want. That will allow 500 photos. I used the M setting on my camera for the jpegs. I was concerned for the file sizes as the L setting is 21mb and I don't know if my laptop could handle the processing of hundreds of files that size. I will experiment however. I am using a light box and turntable. I can turn up the light and lower the ISO speed as well. This is very exciting. I have a lot of objects such as small engine parts that I want to print on the 3D printer and use as models for aluminum casting ( by melting the PLA 3D print plastic out of the mold ). Zephyr looks like it will be perfect for this. The cost of the Lite version is fairly significant for a home hobbyist. Hopefully the Brexit mess will lower the value of the Euro before I have to convert from Canadian dollars.

Thanks a bunch for the help with this problem. I am very impressed with Zephyr as a photogrammetry program. I especially like the ease of masking the objects. No other program that I have tried does this.

[Andrea Alessi]

Happy to help! Feel free to ask anything anytime!

(Brexit will likely pump the euro rather than weaken it though, it's the british pound that has taken a beating and will likely fall. Luckily for us )