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Author Topic: texture requests and some other questions..  (Read 9905 times)

mala

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texture requests and some other questions..
« on: December 09, 2011, 02:33:56 AM »
First off this is mix of suggestions and questions..so not really sure if it should be here or the general forum

I've been using Photoscan for quite a while now,I'm very happy with the mesh it builds...but i have a few problems with the texturing side of things.

I'm working with a fixed camera rig, only 3 cams at the moment but will be expanding it.

I am photographing faces/heads..the person sits inside a dome of controlled LED lights that i have built,the lights are programmed to run through a sequence whilst the cams take a shot at every step of this sequence.
The setup is similar to Debevecs 'Lightstage'...the point of the 'special' lighting is to achieve a normal map that can add a high level of fine detail to the mesh that i get from photoscan.

I use the first shot(GI-all lights on) from each camera in photoscan to build the mesh.

My first issue is that if i use photoscan to build the UV's and textures then the blending is really not very good...it gives a lot of visible smears and almost semi transparent 'ghosting'.

What is the method used for the blending?...i'm interested in this because i have built a rig/node setup in cinema 4D that blends photos that are camera mapped to a head mesh and it seems to work a bit better than the photoscan blending even on a much lower res mesh.

At the moment my only alternative in photoscan is to use the 'single photo' option  to make the texture from each camera then export to photoshop to clean up.
To aid with this method it would be great if a layered file could be exported with masks for the image from each camera.

Due to my 'special light rig' i also have another problem with the texturing in photoscan.
Once i have built my mesh using the GI photo from each camera..i want to be able to swap the GI image out and replace with another image lit differently but taken from the same camera..to generate other texture maps on the same mesh
The only way i can find to do this is by renaming my photo..which is a very clumsy and confusing method...is there an alternative that does not involve rebuilding the mesh?
I know that its maybe a very specialist request, but it would be great to make this image swapping easier..it can't be that complicated can it?

General questions and a bug? :

When exporting model and cameras from photoscan using collada....if i tick the 'separate chunks' in the export options, then when I open the file in cinema 4D i get a model...if i don't tick this box, the file is opened by cinema 4D but contains nothing...but i don't want 'separate chunks' just one mesh.

There seems to be some strange random rotation and scaling issues with the exported models+cams
everything is often rotated by 90? and the axis is never in the middle of mesh...this can be a real pain,can anything be done about this?

Which parts of the build process are multi-threaded and whats the roadmap on this,will there be any changes?

Sorry if that sounds like a long list of complaints,but i do really love photoscan..the level of detail i'm getting using just a few photos is amazing.

Cheers,
mala

Infinite

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Re: texture requests and some other questions..
« Reply #1 on: December 09, 2011, 07:40:48 PM »
Some very good points Merry, I have to also agree about the texturing side of things, when using Multiple Cameras. As for organic captures we need something a bit more robust. Less seams, less random artifacts and Ghosting. Perhaps with User Selected multiple Viewpoint Camera Projections and blending? with more clean texture plates rather than scrambled atlas?

I also agree about the naming conventions and swapping out images to re-texture with, it would be better to be able to point the Image sets to a new folder and have control over their location pointing? and be able to adjust to search for different prefixes? or suffixes? like:

Build set:
GI00001.jpg, GI00002.jpg

then re-point to

Texture set:
L100001.jpg, L100002.jpg etc

Best,
Lee
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I N F I N I T E
www.ir-ltd.net

mala

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Re: texture requests and some other questions..
« Reply #2 on: December 11, 2011, 01:07:36 AM »
Yep you put that a bit clearer than me..cheers Lee

Also i forgot to mention....why can't you 'Keep UV' when you using the single photo texture option?

Cheers,
mala

Alexey Pasumansky

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Re: texture requests and some other questions..
« Reply #3 on: December 15, 2011, 01:53:30 PM »
Hello mala and Lee,

Thank you for your suggestions.

Quote
Which parts of the build process are multi-threaded and whats the roadmap on this,will there be any changes?
In PhotoScan 0.8.3/0.8.4 all steps except the Generating Mesh stage are multi-threaded. But currently we do not plan to parallelize Generating Mesh (at least not in 0.8.5).

Quote
why can't you 'Keep UV' when you using the single photo texture option?
Single Photo parametrization is quite different from other mapping mode types and you will not get anything good if   it would be possible to keep UV for single photo mapping from another camera. But if you swap the images for the same camera using Single Photo option would give you the same parametrization.
Another way is to disable all but one photo in the active chunk and build the texture, then leave enabled another single photo and rebuild the texture keeping UV.
Best regards,
Alexey Pasumansky,
Agisoft LLC

mala

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Re: texture requests and some other questions..
« Reply #4 on: December 19, 2011, 04:08:08 PM »
Thank you for the information Alexey.

I am getting quite good results using the method you suggested,use Mosaic and disable/enable photos with Keep UV enabled on a mesh that is UV'ed in another App.Then swapping photos out,would be very handy if the image swapping could be made easier though as Lee and I suggested.

Here is a Render of recent scan i've made using Photoscan and my normal map method for extra detail,photos taken inside my LED Dome.


eduardoestrada85

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Re: texture requests and some other questions..
« Reply #5 on: October 25, 2012, 05:17:01 AM »
Exported various textures? or are coming together as it enables / disables the images.

That is exactly how and when to apply uv keep?

It is possible  screenshots of the  process please

tnx in advance.

Eduardo.