How can I improve the texture blending?

[DMG]

Greetings,

I have used 3DFZephyr Lite to capture a desktop, which has a wood texture I wanted. The final textured mesh has clear angled banding where different photographs have been used to compile the final merged texture.
I used a high density point cloud, a high-detail mesh (though I'm doubtful either of those will affect the texture generation too much), and used 'aggressive' colour balancing, which did make a big difference compared to my first attempt.

Here's a close-up screengrab of a portion of the final textured object:



Now, a few caveats about the photographic capture itself. I had no control over the lighting, and the desk was quite polished/smooth, and practically every direction I looked, and every position I stood in, it was catching reflections from lights or windows. I took 72 photographs in all, which for a non-reflective surface 2' by 4' would normally be overkill, but I was trying to capture areas with as little reflections as possible. I was using my polarising filter on my camera as well, which was a big help.

Anyway, taking more photographs is not an option. The desk is now firewood.

Are there any settings in Zephyr (Other than the 'aggressive' colour blending option in the advanced options) which will help produce a smother, more gradual blend between different ?images? Or will I have to work on it in a photo-editing software to try and even it out by hand?

Regards,

Derek

[cam3d]

Hi DMG

When source images have really inconsistent lighting there is only so much recovery which can be done with software. Here are my suggestions:


- Light control is really important: Using a cross polarized setup will help massively with reflections on most surfaces but I understand that this is not always possible. Light diffusion with soft boxes, or simply a white sheet draped over a window will help, or simply a nice bright, cloudy & still day can do wonders to spread light nice and evenly across a surface.

- Regarding software solutions: Try and avoid manual touch-ups as they will likely be massively time-consuming (and potentially fruitless), instead I recommend reducing contrast, boosting shadows and dropping highlights globally in a program like Adobe Lightroom. When editing in a third party program make sure not to accidentally correct the image lens distortion as this is accounted for when processing in Zephyr.

- Keep using aggressive colour balance in Zephyr

- Advanced: Look into editing the UV'd texture map in post production - Using Photoshop (or similar) you can use the healing brush and content aware fill to fix things up a bit. If you can create a nice clean UV map with minimal seams 2D texture edits become much easier (pic for reference) - Otherwise you can edit raw UV mapped textures in 3D space using something like Substance Painter - Either way there's a bit of a learning curve!

[Andrea Alessi]

In addition to what Cam said, I also suggest playing a bit with the blending options in the texture generation directy in 3DF Zephyr:

- when you start a new textured mesh project, you are given the option to select which images will be used for texturing. I would start here by removing the most underexposed/overexposed images. Given that the subject is simple, I think you can afford losing a lot of cameras for this step.

- switch to advanced and try changing the parameter for "Color Balance Strenght".

- eventually you can try disabling the multiband options, by changing it to 0 from the deafult 1 by switching to advanced. I generally suggest leaving this to 1, however in some limit cases you may get better results. This could be one of those cases, depending on the type and amount of photos.

Anyway, taking more photographs is not an option. The desk is now firewood.

this is now one of my favorite quotes from this forum

[DMG]

Hi guys,

Thanks for your suggestions.

Cam: I agree there's only so much software can do, and in fairness, so far 3DF Zephyr has done a pretty good job all things considered. Believe me, I know all about ideal lighting conditions, but this was a location out of my control, and I only had a brief window of opportunity. Sadly there were large windows in the room, along with lights everywhere.
You're right, I wouldn't dream of fiddling with the individual photos before processing. I suspect "that way lies madness..." If I end up manually fixing the banding, it will be the final image, and probably with a couple of adjustment layers in PS for saturation/brightness, etc. It wouldn't have occurred to me to try the healing brush, but I'll have a play with that and see what it can do in these circumstances.

Andrea: Good suggestion about removing some cameras from the texturing solution. It's not so much that they're over or under exposed, but every shot is catching a bit of shine in some direction. If I can get the whole surface covered with fewer cameras, then hopefully the worst-case scenario (of fixing it manually) should have fewer areas where textures join.
I've been using the 'colour balance strength' already. The first attempt using the standard or default setting had very noticeable joins. The 'aggressive' setting helped a lot. I was looking at the options on the custom panel to see if this can be cranked up even further, but I couldn't spot anything which looked like it did that.
I have had a quick test with the multiband setting, but it didn't make a noticeable amount of difference for me.

Plan of attack: Fewer cameras for the texturing creation, then probably a bit of manual tidy-up.

Cheers

Derek

[CG-Guy]

Substance Painter

[DMG]

Alas, Substance Painter is out of my budget. Besides, I try to avoid subscription-based models.
I use 3DCoat and PixPlant for some texturing tasks.

[CG-Guy]

They monthly now? Glad I haven't updated my license

[DMG]

Unless I'm mistaken it's part of the Substance Designer suite Adobe bought and now peddle.

[DMG]

I've been mulling this over, and have come up with a 'Plan B'.

I tried Andrea Alessi's suggestions, including limiting the number of cameras used to generate the texture. Because of the properties and diffuse reflections on the wood, it still left me with quite noticeable banding which would require dealing with. So I took the idea to the extreme.

I created a retopo .obj with UVs of the top of the desk and imported this into 3DZephyr as a textured model, but only selected a single camera.

?

?This gave me an image within a tidy rectangular UV. I have repeated this for various cameras, then exported the textures, and built up a photoshop document which I am blending myself with layer masks and levels adjustments which I can paint myself to follow the mellowing of the wood and the grain. I've done about a fifth of the desktop with only five images, and the result is quite promising. Yes, it's a manual process, but in this instance it's giving me complete control over the result.

So far, so good.

Derek