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Author Topic: Texture pixelated  (Read 14213 times)

Alexey Pasumansky

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Re: Texture pixelated
« Reply #15 on: November 10, 2014, 12:19:04 PM »
Hello MitoTheGreek,

Thank you for providing the project file.

There are tow main reasons of the pixelated texture problem for the given dataset:
1) The polygon number corresponding to the car is even less than one percent of the total number of polygons (and so the area corresponding to the car is hundreds times lower than the area of the whole scene),
2) And the effective resolution of the car on the original images is also low, so practically there is almost to information to perform good texturing for the car in the given project.
Best regards,
Alexey Pasumansky,
Agisoft LLC

MitoTheGreek

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Re: Texture pixelated
« Reply #16 on: November 10, 2014, 02:27:52 PM »
ok so take closer pictures. What about with the bear? those pictures were really close.

Alexey Pasumansky

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Re: Texture pixelated
« Reply #17 on: November 10, 2014, 02:33:31 PM »
Hello MitoTheGreek,

Try using Mosaic blending for the texture generation. Also the blurred texture may be related to some alignment problems.
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Alexey Pasumansky,
Agisoft LLC

MitoTheGreek

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Re: Texture pixelated
« Reply #18 on: November 10, 2014, 02:36:49 PM »
I have used the mosaic blending as well. How can i better the alignment, because there should be little blur since the pictures are 3-5 away from the target?

Alexey Pasumansky

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Re: Texture pixelated
« Reply #19 on: November 10, 2014, 02:40:18 PM »
Hello MitoTheGreek,

Then maybe you can send this project as well with the original image set?
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Alexey Pasumansky,
Agisoft LLC

MitoTheGreek

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Re: Texture pixelated
« Reply #20 on: November 10, 2014, 02:41:25 PM »
I will do that right now.

Alexey Pasumansky

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Re: Texture pixelated
« Reply #21 on: November 10, 2014, 05:50:30 PM »
Hello MitoTheGreek,

Many images from this dataset are blurred, also the focal depth is quite shallow to capture all the objects' details, so it results in focusing on the small area only. As a result the reconstructed dense cloud and mesh are not accurate and projected texture is blurred.

Since rather long shutter speed is used I can suggest to use tripod for image acquisition, as it will also allow to use higher f-stop values (f/8 or so).
Best regards,
Alexey Pasumansky,
Agisoft LLC

igor73

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Re: Texture pixelated
« Reply #22 on: November 13, 2014, 07:34:48 PM »
I usually don´t use the Agisoft generated UV´s.  Best way is to generate new UV´s in a 3D app.  It can be a bit complicated workflow though.

 If you want a quick fix try this.  I have noticed that you get pixalated results when the mesh has  to high polygon count.  What is your polygon count on these models?   Try decimate to 500k to 2 million and you should get clear textures. There is a decimate function in Agisoft.    This has worked for me anyway so worth trying if you don´t want to spend time learning to use  Blender. 

Note,  did ot read Alexeys replies before posting. So my suggestions might  do you any good in this case.  You seem to  have issues with blurred photos.  Crap in - crap out is usually the result. 

« Last Edit: November 13, 2014, 07:37:36 PM by igor73 »

MitoTheGreek

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Re: Texture pixelated
« Reply #23 on: November 15, 2014, 07:27:08 AM »
Thats a lot of steps to UV in blender. Is there any program that can auto UV?

igor73

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Re: Texture pixelated
« Reply #24 on: November 16, 2014, 08:51:49 PM »
Zbrush has a feature thats called UV master that is just brilliant at auto UV mapping.  It will not work  on a typical scan data mesh though.  It need good topology so you have to do several steps to get the mesh up to scratch. All of that can be done with Zbrush.  Sometimes a slow work flow though.

You could UV map automatically to AUV tiles in Zbrush  but not sure if a UV like that has any advantages over the PS UV.  Seems like PS is also using a similar approach to AUV tiles.  In AUV tiles each polygon gets its own pace in the UV. If your mesh has 10 million polygons you can imagine the resulting UV mesh.  Same thing with a PS generated mesh. Decimate it..  http://docs.pixologic.com/reference-guide/tool/polymesh/uv-map/

Zbrush is a 800 USD software to. 

The only reason to not use the PS UV is better use of texture space and editable textures.  .  Often i see only 20-40% of texture space used in PS generated UV´s. That means you will lose resolution.  Also if you want to edit  the texture or generate normal maps, spec maps etc a tiled mesh won't work well.  If you just need the texture for renders it will most often be fine using the PS generated mesh and not worth the effort turning it in to a proper UV. Generate a 8k texture or even 16k texture  and you will get plenty of resolution anyway.  You can render using high ploys instead using a PBR render engine. A normal map will do very little  effect on a high poly mesh.  The best normal map after all is the real thing, a high poly mesh. 

So try decimate the mesh to a mors manageable poly count and see if your texture improves. 

I am not aware of any 3D app that can auto generate good UV´s from scan data with out modification .I high poly mesh is a nightmare to UV unwrap.  If anyone does i  would like to know as well.