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Re: Post your Point Clouds Here!
« Reply #10 on: June 14, 2008, 06:19:32 PM »
Does anyone have an actual point cloud file they can send me?  I have a program called Vrmesh that is specifically for creating meshes from point clouds.  It a great program but a bit pricey.

Thanks,
Andre
Re: Post your Point Clouds Here!
« Reply #11 on: June 14, 2008, 10:59:27 PM »
Here ya go...
Re: Post your Point Clouds Here!
« Reply #12 on: June 15, 2008, 11:36:01 PM »
Here is the point cloud that goes with the mailbox key JPEG that I posted previously.

Tom Hubin
thubin@earthlink.net
Re: Post your Point Clouds Here!
« Reply #13 on: July 04, 2008, 02:31:28 AM »
Hello,

Here is a single pass scan of a boxend wrench. yStep is 0.010 inches. Speed is 5ipm.

The wrench measures about 5.5 inches but shows up in Rhino as closer to 5.0 inches.

Camera is a PlayStation 2 (silver color housing, not the black version) with exposure control set at 1.
Higherst exposure setting would be 130 and lowest setting would be zero.

Laser is a 5vdc, red (I forget which wavelength) module from Aixiz. The laser module is gettting power from a second USB port. 
I did not get this on ebay since Aixiz does not list their 5vdc modules with adjustable lenses.

Computer is 800MHz Dell Inspiron 8000 laptop.

Tom Hubin
thubin@earthlink.nety
Re: Post your Point Clouds Here!
« Reply #14 on: July 12, 2008, 02:59:27 PM »
Hello,

Here is a single pass scan of a penny. yStep is 0.010 inches. Speed is 5ipm.

The penny is 0.75 inch diameter. This appears to be correct in the Y direction but more like 0.87 shown in the X direction.
I was guessing at the camera FOV. I will try to get the scaling right another time.

Camera is a Digi Watchport/V2 640x480 CCD webcam with exposure control set at about 1ms.
Exposure range is anywhere from 1/30000 sec to 1/4 sec.

Laser is a 5vdc, red (I forget which wavelength) module from Aixiz.
The laser module is getting power from a second USB port. 
I did not get this on ebay since Aixiz does not list their 5vdc modules with adjustable lenses.

Computer is 800MHz Dell Inspiron 8000 laptop.

Attached Txt file is the point cloud produced by Mach3.
Attached Gif file was produced by Rhino.

Tom Hubin
thubin@earthlink.net
Re: Post your Point Clouds Here!
« Reply #15 on: July 13, 2008, 12:54:12 PM »
Hi Tom,
Very neat your penny scan. I would like to reproduce it and I have two questions.
1. I would love to see a print screen of the 3DVideoProbe panel to make the scan of the penny. Could you please post it ?
2. I have loaded the file thubin080712CloudPenny03.txt in MachCloud but when I go to mesh it  the cloud disappears :o  and no mesh is being done. Have you mesh that cloud?
If yes what settings do you make on the BallPivot mesh panel?
Thanks,
Gaston
Re: Post your Point Clouds Here!
« Reply #16 on: July 13, 2008, 06:17:49 PM »
Hello Gaston,

> 1. I would love to see a print screen of the 3DVideoProbe panel to make the scan of the penny.
> Could you please post it ?

I have posted a scan setup from today. The video shows a single line through the center of the penny. Exposure time was set at 1/3840 seconds and the resolution was 640x480. Mirror (left to right) and Flip (top to bottom) were selected since the camera is upside down.

I think that only the FOV is different. I changed it from 18.1 degrees to 15.4 degrees and got better proportions on the penny. This is about right for the +12mm focal length lens that I use on the Digi Watchport/V2 camera.

> 2. I have loaded the file thubin080712CloudPenny03.txt in MachCloud but when I go to mesh it the cloud disappears and no mesh is being done.
> Have you mesh that cloud? If yes what settings do you make on the BallPivot mesh panel?

I have had very little success with any of MachCloud's features. I have been using the free evaluation version of Rhino but have done little with it other than display and measure pointclouds.
I have figured out how to delete points from the cloud in Rhino. Never could get that to work right in MachCloud.

I could not get meshing or any of that kind of stuff working in MachCloud.  I have not tried that in Rhino.

What camera are you using? Do you know the lens focal length? Do you know the field of view?

Tom Hubin
thubin@earthlink.net
Re: Post your Point Clouds Here!
« Reply #17 on: July 15, 2008, 12:27:06 AM »
Hi Tom,

>I have posted a scan setup from today. The video shows a single line through the center of the penny. Exposure time was set at 1/3840 seconds and the resolution was 640x480. Mirror (left to right) and Flip (top >to bottom) were selected since the camera is upside down.

Thank you, that was very useful. I do not have the facility to set the exposure time, the camera is taking 29.970 frames/sec and that's it.

>I think that only the FOV is different. I changed it from 18.1 degrees to 15.4 degrees and got better proportions on the penny. This is about right for the +12mm focal length lens that I use on the Digi Watchport/>V2 camera.

I have set the FOV to 70 which when calibrated with a 1" Styrofoam block give a distance approx right. The x-y dimensions seem also right.

>> 2. I have loaded the file thubin080712CloudPenny03.txt in MachCloud but when I go to mesh it the cloud disappears and no mesh is being done.
>> Have you mesh that cloud? If yes what settings do you make on the BallPivot mesh panel?

>I could not get meshing or any of that kind of stuff working in MachCloud.  I have not tried that in Rhino.

It seems that if the dimensions of the object are too small (not the number of points in the cloud) meshing swallows it ??? 

>What camera are you using? Do you know the lens focal length? Do you know the field of view?

http://www.supercircuits.com/Security-Cameras/Board-Cameras/PC302XS with a digitizer The resulting image is 640x480 and black and white

I have found that the if I lower the voltage on the laser line generator I get a cleaner image of the line.

I have to work on my setup so I can change the distance between the camera and the laser easily. Right now the laser is pointing straight down and the camera is at ~45deg.

As for meshing in Machloud:
I do not understand what the Delauney Set is used for ???
BallPivot mesh seems to works ok with the Prop.txt supplied by Art but I have not so far succeed to pick winning values for the Ball Diameter, shortest Edge and Max Angle to produce the same kind of results on anything I have scan so far. I am using inches dimensions. I wish somebody could explain how to set those parameters?

Regards,
Gaston

 
Re: Post your Point Clouds Here!
« Reply #18 on: July 15, 2008, 03:18:45 AM »
Hello Gaston,

> I do not have the facility to set the exposure time, the camera is taking 29.970 frames/sec and that's it.

On the Video Probe screen, select Stop Video then select Source and/or Format to see if you have any exposure or resolution options. Then select Start Video to resume. Don't be surprised if Mach3 crashes when you try this.

You may find similar options with the camera vendor's software. Sometimes you can setup your camera options with the vendor's software and Mach3 will use that setup. I can send you stuff for other cameras that seems to be fairly generic.

> I have set the FOV to 70 which when calibrated with a 1" Styrofoam block give a distance approx right.
> The x-y dimensions seem also right.

I see that the camera is shipped with a lens for 70 degree FOV. The lens is replaceable. I suspect that the thread is M12-0.5mm. If so, you can get lenses on ebay. Search for M12* and lens* in title and description...or I can point you to some I have seen listed. I intend to get some of these M12-0.5mm threaded lenses from ebay but have not yet done so.

With a 70 degree field of view you will be able to look at large items in coarse detail. You will not get enough detail to pick out Lincoln's head on a penny. You will also have a good deal of distortion. You probably can determine by diameter that the coin is a penny, nickel, dime, quarter etc. To reproduce my results you will need a 12mm focal length lens or longer.

> > What camera are you using? Do you know the lens focal length? Do you know the field of view?

> http://www.supercircuits.com/Security-Cameras/Board-Cameras/PC302XS with a digitizer.
> The resulting image is 640x480 and black and white.

Black and white is good. Color info is not useful and results in larger data transfer that takes longer to transfer and process. Also, B&W cameras usually produce sharper images than color cameras. 

> I have found that the if I lower the voltage on the laser line generator I get a cleaner image of the line.

That is probably due to saturation of the CCD array. The fix is to reduce the exposure time or sensitivity of the camera. When you reduce the laser power you also reduce the CCD saturation, so that helps, but this does not reduce background noise like reducing exposure time does.

> I have to work on my setup so I can change the distance between the camera and the laser easily.
> Right now the laser is pointing straight down and the camera is at ~45deg.

Neither the camera nor the lens should be pointed straight down. The camera and the lens need to be pointed 90 degrees apart. I have chosen to have the laser 30 degrees CW from the Z axis and the camera 60 degrees CCW from the Z axis, as shown here: http://www.machsupport.com/forum/index.php/topic,5023.msg42913.html#msg42913 .

> As for meshing in Machloud:
> I do not understand what the Delauney Set is used for ???
> BallPivot mesh seems to works ok with the Prop.txt supplied by Art but I have not so far succeed to pick winning values > for the Ball Diameter, shortest Edge and Max Angle to produce the same kind of results on anything I have scan so far. I > am using inches dimensions. I wish somebody could explain how to set those parameters?

Sorry but I am also clueless there.

Tom Hubin
thubin@earthlink.net
 

Quote
Re: Post your Point Clouds Here!
« Reply #19 on: July 15, 2008, 08:57:41 PM »
Hi Tom,
>Neither the camera nor the lens should be pointed straight down. The camera and the lens need to be pointed 90 degrees apart.
> I have chosen to have the laser 30 degrees CW from the Z axis and the camera 60 degrees CCW from the Z axis

As the same setup is used both for calibration and measurement why 90 deg be so important?
I see that the amplitude of the deviation would be maximized with 90 deg but as I understand it the results would not be more valid.

Gaston