export formats

[roger johnson]

On the 4th June 2018, Andrea suggests that gbl is a supported export format.

is this true? I cant see it in the list of mesh export optionts.

[roger johnson]

seems it is available for textured meshes ..

by why not for non textured ?

non textured meshes appear to provide much better surface colour / detail

[roger johnson]

...............and that begs the question of how to limit the file size if there is no maximum no. of vertices option for GLB files??

Im currently creating file sizes of around 250Mb when the target system recommends files of no more than 50 Mb

[cam3d]

Hi roger johnson

A mesh and a textured mesh generated in 3DF Zephyr will have identical mesh surface properties unless you manually adjust the max vertex limit in advanced textured mesh settings (or are using the low poly preset in the textured mesh wizard which sets the max vertex limit to 200,000).

.GLB is a version of .GITF which is binary and stores all data internally (textures etc..) with nothing stored/referenced externally (e.g .OBJ + .MTL +.JPEG). There are two main components to consider in this instance:


MESH:
You can set your max vertices in the textured mesh wizard which gives a predicable file size for your 3D mesh.

TEXTURE:
.PNG uses lossless compression and therefore has a predictable file size based on output resolution.
.JPEG uses lossy compression and therefore has an unpredictable file size which is independent of output resolution.

It makes a lot more sense to use JPEG with .GLB as .GLB aims to be a lightweight, high price performance delivery format and therefore benefits greatly from lossy compression.

.GLB doesn't support multiple texture inputs (UDIM etc..) so best to generate a single texture rather than have Zephyr combine multiple as an export workaround.

If you don't need to bake textures into a .GBL you probably don't need a .GBL and the better option would likely be .OBJ - It might be trivial to add .GLB as a non-textured export but that's beyond my understanding so pinging Andrea Alessi re: that.

Long story short: If you set your max vertex count in textured mesh generation settings to 128,000 vertices (256,000 tris) and generate a 8k*8k texture to be exported as a JPEG, you'll be well within the 50mb limitation of your target system -

[roger johnson]

can we go back a bit . .. and confirm a basic mesh




produces a better resolution than a textured mesh?

[Andrea Alessi]

The textured mesh may have a lower polycount depending on your settings, or it can have the very same geometry of the mesh.

From your screenshot it seems a texturing issue rather than a geometry issue. You may have wrongly oriented cameras that are contributing the wrong colors, so double check your cameras / make sure you didn't pick the wrong directory/photos if you moved your project as if the reference is broken so will be the texturing. If you want to share the dataset we're happy to have a look.

[roger johnson]

Hi Andrea


thanks for your suggestions although I am not entirely sure how to check for wrongly orientated cameras and what to do if they are.

I'm still very much a zephyr novice trying to figure out how to get the best detail from wood carvings .

As can be seen in the non textured mesh snapshot, there is is quite a lot of fine surface detail on the clothes and the body markings of the deer which I want to preserve

So I have tried to use the best reconstruction settings for the different zephyr phases


a) sparse cloud (basic option) > surface scan + deep

b) dense cloud (advanced option) > surface scan + high details

c) mesh extract (advanced option) > watertightness 100%

d) texture extract (basic option) >

Having generated two object files (mesh_1export @ 471mb and textured_mesh_1export @ 578mb), I then open them up using meshlab.

Using prt sc to capture meshlabs summary info, the screenshots show that the vertices count are the same so it does not appear to be a poly count difference.

It appears that mesh_1export @ 471mb is clearly producing a better image


compared to textured_mesh_1export @ 578mb.


Ive probably completely misunderstood but given the choice it would seem that I should be able to produce a 3d glb file directly from the non textured mesh?


Do want me to upload the two obj files?

If so how?

Thanks

[roger johnson]

textured mesh

[roger johnson]

non textured

[cam3d]

roger johnson - Meshlab doesn't support multi-tile textures so that's the likely issue here, when you're setting up the texture settings make sure to select default single texture, or specify the max number of textures to 1 in advanced textured mesh settings.

You can share files with us using a service like Google Drive or We Transfer and you can either post the link here, or send it to us at support@3dflow.net

[roger johnson]

ok cam3

many thanks again

Ive uploaded the two object files as suggested via wetransfer using the support address so you can see if there is anything obviously wrong .

Im a little reluctant to send the source dataset at this stage but hope to find a file conversion utility to GLB format. The main problem is the file size.

I assume that the obj texture file in zephyr have a maximum size . do you know what it is|?

As regards the multi tile issue if either the preset or advanced option is chosen then a single texture is set.

[cam3d]

roger johnson Thanks for sending those .OBJ files through.

I can confirm that they have identical mesh properties - There were no texture files in the download link you sent through so I was unable to check the textured mesh properly - It does look like a single textured mesh based on the UV map so it's strange that it would be showing up jumbled in meshlab - Can you please send the texture file through too?

To my understanding, there's no maximum size for OBJ files, but they will get pretty dysfunctional beyond 50m vertices.

You will need to decimate your mesh before trying to export as GLB.

As I mentioned before, if you set your max vertex count in textured mesh generation settings to 128,000 vertices (256,000 tris) and generate a 8k*8k texture to be exported as a JPEG, you can export as .GLB you'll be well within the 50mb limitation of your target system - There is no way (other than decimation and texture size reduction) to make the model small enough to fit within a 50mb limit.

[roger johnson]

Hopefully the .PNG file attached is the what you are after



hope to experiment tomorrow with your jpeg and .GLB advice !

[cam3d]

Roger - The attached PNG image is only 512*512px - If you could provide a download link for the full image file that would be ideal!