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Posted by rdorsch at Apr 29, 2015, 1:52:56 PM

3D Artefact
Hello,

I see here a 3D artefact, which I cannot explain

http://netcup.bokomoko.de/~rd/sweethome3D/sh3d-artefact.png

I surounded the artefact with red.

The complete model is here

http://netcup.bokomoko.de/~rd/sweethome3D/treppeNO.sh3d

I am running sweethome3D on Debian Linux 8.0

Can anybody confirm the artefact in the model (i.e. that it is a sweethome3D issue and not an issue on my machine)?

Any other hint what could cause this is welcome.

Thanks
Rainer

Posted by hansmex at Apr 29, 2015, 1:56:35 PM

Re: 3D Artefact
Simple problem, simple solution: Uncheck the ceiling in the room on the top floor.

Because of the sloping walls, SH3D has a problem drawing the ceiling correctly. If you want a sloping ceiling in this room, draw two separate rooms for each half of the slope.

Hans
----------------------------------------
Hans

new website - under constuction
hansdirkse.info

Posted by rdorsch at Apr 29, 2015, 3:45:22 PM

Re: 3D Artefact
Thank you, Hans, for the immediate reply.

I understand the uncheck ceiling proposal, which works well.

I do not understand your second proposal with the two rooms though....the room which shows the artefact is "Flur" and "Flur" has only one slope for the entire room (?).

Posted by rdorsch at Apr 29, 2015, 3:50:05 PM

Re: 3D Artefact
I have a similar artefact in the same sweethome3d file for the roof, but seems to be a different root cause.

See

http://netcup.bokomoko.de/~rd/sweethome3D/sh3d-roof.png

I created the roof myself following a howto. Unfortunately I lost my source file, is that the same issue and I would have to remove the ceiling again in the source file?

Posted by okh at Apr 29, 2015, 4:11:28 PM

Re: 3D Artefact

...I created the roof myself following a howto. ..

When you export your .obj file, make sure to EXPORT SELECTION only (not the entire model). If you do not want to make it again, you could apply an invisible texture to that part of your object. ok

Posted by rdorsch at Apr 29, 2015, 7:30:46 PM

Re: 3D Artefact
Thank you for your reply. Applying an invisible texture to part of an object does not works inside sweethome3d and I need an external tool, correct?

Posted by okh at Apr 29, 2015, 8:00:42 PM

Re: 3D Artefact
No need to worry, it does work from SH3D. If you apply an invisible texture (a totally transparent .png) to your ground_1 material, the end shape (ground) will vanish. This, btw, is a nice general trick to make elements of some objects vanish.

ok

(You could also add transparency in the .mtl file, but then it is probably better to save the roof as an .obj only exporting selection).

Posted by rdorsch at Apr 29, 2015, 11:14:05 PM

Re: 3D Artefact
Many thanks for that very useful response.

I used

http://www.sweethome3d.com/blog/2014/08/13/how_to_apply_textures_on_a_box.html

to understand how to apply a texture to my ground_1 material.

Posted by rdorsch at May 2, 2015, 1:09:25 PM

Re: 3D Artefact
I found another 3D artefact:

http://netcup.bokomoko.de/~rd/sweethome3D/sh3d-artefact2.png

The ceiling is not closed (although this artefacts is not visible in views from all angles, you need to move the camera around). Note, in this floor the ceiling has no slope. I find that artefact in this sh3d file in the Ess-/Wohnzimmer on level EG:

http://netcup.bokomoko.de/~rd/sweethome3D/treppeNO.sh3d

And there is another one:

http://netcup.bokomoko.de/~rd/sweethome3D/sh3d-artefact3.png

This one can be seen e.g. inside Küche on level EG.

Are these also known issues?

Thanks
Rainer

Posted by hansmex at May 2, 2015, 2:13:09 PM

Re: 3D Artefact
Rainer,

I checked both rooms in your design: there is nothing strange to see.
All walls are the same height, so it would be very strange if something strange would be visible.

Maybe, you have a somewhat older computer, or your video drivers are not uptodate?

(Checked with Ubuntu 14.04 64 bits, SH3D v4.6)

Hans
----------------------------------------
Hans

new website - under constuction
hansdirkse.info

Posted by rdorsch at May 2, 2015, 3:53:22 PM

Re: 3D Artefact
Hi Hans,

thank you for your quick response.

Hmm, my software is new, my hardware is indeed older....I run SH3D 4.5 on a Debian Linux 8.0 system. The graphics hardware is Intel based, which is typically well supported on Linux systems

00:02.0 VGA compatible controller: Intel Corporation 82G35 Express Integrated Graphics Controller (rev 03) (prog-if 00 [VGA controller])

I.e. I would expect may slow behavior, but not wrong rendering. The artefacts are perfectly reproducible, they are also static, i.e. when an artefact is visible and I stop moving the artefact stays. The artefacts slowly become bigger and smaller when I change the angle of view in the room.

Can sweethome3d generate logs, which might be helpful in understanding what is going on?

Kind regards
Rainer

Posted by hansmex at May 2, 2015, 4:13:26 PM

Re: 3D Artefact
Rainer,

I'm not familiar with Debian, nor with hardware. So, I don't have specific recommendations for you. I'm using Ubuntu for close to 10 years now, and I know SH3D works well. In Ubuntu there can be a conflict of Java; my solution was to uninstall all Java lookalikes and install Oracle Sun Java.

Most other problems I've seen here over the years have something to do with incompatible hardware or drivers. So, that's where I would look first. Did you read the suggestions in the FAQ?

Another suggestion: try to render a photo in Q3 or Q4. Probably the artefacts will disappear, as these renders depend on software, not hardware (like Q1 and Q2).

I also suggest upgrading to SH3D v4.6, it's easy enough.

Here are the results I get with quality setting 3. Also, perfectly reproducible. Q1 and Q2 also look as expected with closed ceilings.

kitchen

living

----------------------------------------
Hans

new website - under constuction
hansdirkse.info

Posted by rdorsch at May 2, 2015, 5:58:59 PM

Re: 3D Artefact
Hans,

many thanks again for the immediate feedback. Indeed, I can confirm that rendering a photo with Q3 or Q4 produces a correct output, whereas Q1 or Q2 produce the ceilings with gaps.

See e.g. http://netcup.bokomoko.de/~rd/sweethome3D/sh3d-artefact4.png

Are Q3 and Q4 using sunflow? Do you know through which mechanisms or libraries the HW is accessed in Q1 or Q2? Java 3D?

Are you using java6 ? I have here

I read now through the FAQ, but did not find anything I could relate to my issue....did you have anything specific in mind?

Thanks
Rainer

Posted by hansmex at May 2, 2015, 6:23:24 PM

Re: 3D Artefact
Rainer,

Q1 and Q2 depend on the hardware of your computer, especially the 3D capabilities of your video card and driver.
Q3 and Q4 are hardware-independent; they use the SH3D software, including Sunflow for rendering.

The installed version comes with its own Java. That's the version I always use. You could try the webstart version and/or the online version to see if there is a difference.
For more technical info, ask Puybaret.

And, no, I didn't have anything specific in mind when referring to the FAQ. Just hoping that one of the suggestions there might be helpful.

H
----------------------------------------
Hans

new website - under constuction
hansdirkse.info

Posted by rdorsch at May 2, 2015, 7:08:37 PM

Re: 3D Artefact
Hans,

I have now a case where I see an artefact in Q3 and Q4 but not Q1 and Q2:

http://netcup.bokomoko.de/~rd/sweethome3D/sh3d-artefact5.png

I would have expected the outer wall to be flat, but it seems to have a strange step on the right half.

The rendering is taken with Q4 on the same sh3d file as before.

Do you have any idea what goes wrong?

Thanks
Rainer

PS: I am downloading 4.6 to install it on the side.

Posted by rdorsch at May 2, 2015, 8:12:55 PM

Re: 3D Artefact

I also suggest upgrading to SH3D v4.6, it's easy enough.

I did that, but that did not resolve any artefact issue. The software artefact become rather somewhat worse (rendered with Q3, not clear where the structure between the second and thrid floor comes from):

http://netcup.bokomoko.de/~rd/sweethome3D/sh3d-artefact6.png

It uses the included java version.

Rainer

Posted by hansmex at May 2, 2015, 11:37:39 PM

Re: 3D Artefact
Once again I opened your file and was able to reproduce an artefact. Not exactly the same as yours, but similar, and not easily explained.

This is what I did:
- open file
- switch to Aerial View
- select Create Photo
- set quality to Q3
- render image --> there is a small artefact above the window

Then I did the following
- zoom in on the house using the scroll wheel on my mouse
- make another photo --> there is a small artefact above the window

Both images were made WITHOUT changing the view by rotating the image
After slightly rotating the 3D image, the artefact persists. It's the same in all pictures. (Q3 - 400x400 pixels)

NOTE
I checked wall heights (okay), level heights (okay), wall textures (none), etc. I couldn't find anything out of the ordinary.
NOTE 2
When I delete the two windows under the roof and insert them again, the artefact has disappeared.

----------------------------------------
Hans

new website - under constuction
hansdirkse.info

Posted by rdorsch at May 3, 2015, 12:32:00 AM

Re: 3D Artefact
Hans,

thank you for looking into that and I am glad that you were able to repro the issue.

I made these windows invisible and later visible again. Then also the issue disappeared. But after rotating the building somewhat forth and back, it came back.... not in exactly the same for though

http://netcup.bokomoko.de/~rd/sweethome3D/sh3d-artefact7.png

To me it seems that sh3d breaks the computation down into grid elements....and some of the grid elements, the computation goes wrong.

Also I noticed that I changed the model somewhat, for completeness I uploaded the latest model

http://netcup.bokomoko.de/~rd/sweethome3D/treppeNO2.sh3d

Kind regards
Rainer

Posted by hansmex at May 3, 2015, 2:22:12 AM

Re: 3D Artefact
When rendering a photo of your new file, I get the same artefact.
Just a different size and in a different place, but VERY similar, consisting of two parts.

It almost looks like an X-ray shadow of two windows.

H
----------------------------------------
Hans

new website - under constuction
hansdirkse.info

Posted by okh at May 3, 2015, 2:07:03 PM

Re: 3D Artefact
Could this possibly be related to SF Bugs 582? Sometimes several SVG cut-outs on one surface (wall or floor/ceiling) appear to be interfering with each other. ok

Posted by rdorsch at May 4, 2015, 8:47:46 AM

Re: 3D Artefact
I saw a relation to the roof: making it invisible: issue is gone, making it visible again, issue is there again.

Note, the roof has an invisible part, see post from Apr 29, 2015 6:00:42 PM above.

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