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Author Topic: Blender Import  (Read 10590 times)

frank.stremke

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Blender Import
« on: April 25, 2013, 12:34:05 AM »
Hi sorry for  general question searched the forum but was not very good at it...
i have created a large model of a query it is about 200m long and 100m wide i whant to have the best textures my computer can handle and crated 25000x25000 pixel textures which looks good for the details i need. but as i understand i can only use 8000x8000pixel textures in blender or am i wrong?
so i whant to reate a clip moving around in the query "flying true the model) using blender how is it posible to keep detailed textures.
would i have to cut the modell into pieces and put it togeter in blender.
best regards
frank

jedfrechette

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Re: Blender Import
« Reply #1 on: April 25, 2013, 02:30:09 AM »
I don't think Blender has any fixed limit on the size of textures you can use. I've used it to do similar visualizations of 1500 km2 regions with ridiculously large 65k textures derived from satellite photos. You may not have enough RAM on your graphics card to use textures this large in the view port but you should still be able to render them. That being said, depending on your hardware, and how complex your model is splitting it up is often the best option.

One side note about texture sizes. For various performance reasons, you should generally stick to square power of 2 image sizes, e.g. 4096x4096, 8192x8192, 16324x16324, 32648x32648. Using power of 2 images also makes it easy to swap in a low resolution texture that is 1/4 or 1/8th the area of the full texture while you are setting up you lights and camera path.
Jed

frank.stremke

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Re: Blender Import
« Reply #2 on: April 25, 2013, 11:19:51 PM »
thanks for that,
what format you would sugest colaborates best with blender. Collanda i presume?
frank

jedfrechette

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Re: Blender Import
« Reply #3 on: April 26, 2013, 12:26:42 AM »
I've haven't specifically tested PhotoScan->Blender via Collada but I've never had much luck with Collada in general.

It's hard to go wrong with .obj and a .tif or .png texture map for standard 8-bit textures, use .exr if you happen to be doing high bit-depth work.
Jed

frank.stremke

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Re: Blender Import
« Reply #4 on: April 26, 2013, 09:56:48 AM »
thanks
there is however the limitation with my hardware even with 32gig ram and nvidia gtx 660 i cna open the object in render (about 500mb) but as i load the texture it crashes and tells me not enough system recources (open gl error)
this is hovever fixed when i use jpg textures they 27mb instead of 163. quality is of course not as good.
anyway if i export it as local coordinates it is fine but if i try UTM in which the whole system was created it just gets very rough and looks strange and simplified.
hoever file size is about the same as in the loc coordiantes even a bit more.
you can see the pictures here
https://www.dropbox.com/sh/lm7twvm4jc3qv31/CNhIe7HRMA
if i whant to combine several models wich are in the same area but not adjoining i thought it might be good to use my coordinate system also for all kind of other advantages i can take readings staight from the model ect.
so i think it is a good feature to export in UTM coordinates but it seems not to work :-( at least for me.
frank

Alexey Pasumansky

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Re: Blender Import
« Reply #5 on: April 26, 2013, 01:28:19 PM »
Hello Frank,

UTM coordinate export works correctly - you can export model in ascii format and check that all vertices have correct coordinates.
More likely the problem is on import side since some 3D editing applications import coordinates as float and the rest is truncated. I suggest you can use Shift feature on export.
Best regards,
Alexey Pasumansky,
Agisoft LLC

frank.stremke

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Re: Blender Import
« Reply #6 on: April 26, 2013, 01:36:49 PM »
thanks
In what way shall i make use of the shift feature then?
how does it work?
only option i dont have the fancy looks is in pdf.
frank

Alexey Pasumansky

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Re: Blender Import
« Reply #7 on: April 26, 2013, 01:50:39 PM »
Hello Frank,

In Shift fields (in Export Model dialog) you can input huge values that will be subtracted from the model coordinates. For example, if you have X,Y coordinates like 12235833.171 and 727355.045
You can input 12230000 and 72000 in the corresponding fields. In this case external applications will open model correctly - could you please check it and inform about the results?
Best regards,
Alexey Pasumansky,
Agisoft LLC

frank.stremke

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Re: Blender Import
« Reply #8 on: April 26, 2013, 02:08:10 PM »
will do asap and report back here but anyway thanks for the info.
thats a nice feature
frank

jedfrechette

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Re: Blender Import
« Reply #9 on: April 26, 2013, 04:43:07 PM »
there is however the limitation with my hardware even with 32gig ram and nvidia gtx 660 i cna open the object in render (about 500mb) but as i load the texture it crashes and tells me not enough system recources (open gl error)

That error means that your graphics card doesn't have enough Video RAM to load the texture & associated mipmaps. I'm not sure what you mean by "but as I load the texture". If the 3D viewport is in solid mode the graphics card should not need to load the texture. If you are trying to use GPU rendering with Cycles it may need to load the entire texture as well so you may be limited to CPU rendering.

this is hovever fixed when i use jpg textures they 27mb instead of 163. quality is of course not as good.

Assuming both of these textures are the same resolution and bit depth I'm not sure why the file format would matter.

Below I've linked a screen shot of my setup for a scene comparable to yours. Notice I have two copies of my mesh, a standard & proxy version. The proxy uses a low resolution texture and is visible in the view port but doesn't render, while the standard version renders but is invisible in the view port. In this case it was a low-resolution mesh so I used the exact same geometry for the proxy but normally I would use a proxy with a lower polygon count than the real mesh.


Jed