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Video P*r*o*b*i*n*g / Re: alpha release of point generator..
« on: November 13, 2007, 01:48:46 PM »
Youll notice two windows on the interfce. The first is the actual video. Youll notice its dark. Thats because the lights are off.
Having lights on makes it very hard to reject specular noise. Youll also notice there is a raised section to the laser line. Thats beacuse there
is a 52mm block of wood on the table. This is the second step to starting up. When YOU start, have nothing in the field. Rotate your laser do the red line in the second
image is as straigth as possible. Then insert the block off wood or obejct to calibrate with., I use a simpel wooden block measured at 52mm high and 52mm wide. width doesnt really
matter, but you want to make sure the line below the block is showing well as well as the line on the block.
The slider between the images is a threshhold. Slide it up and down until you have what looks like a square wave on the line monitor window.
The White line incidently is raw data, the red line is CenterOFMass corrected, and centroided to produce a cleaner line. Lasers can create noisy lines.. so the red line is the
cleaned line. Leave all the numbers alone except for the Cube size, enter the size of your block there. (inches or mm's shoudlnt matter, whatever mode Mach3 is in..)
Then slide the threshold slider for a good square wave so it seems to be sensitive to the edges of the block but with as little noise as you can get, but make sure the
width of the block appears to be seen. Then hit calibrate. Repeatedly hitting calibrate, you should see now the laser angle showing and perhaps varying about .1 degrees, it
may vary more, ( or less) depending on the camera, and the laser. Not too important in organic scanning, but the more accurate is it, the better.. The camera height should now
show pretty close to how high the cameras focal plane actually is..
On the point control, you can see its set to reject any Z's less than 1mm, this just gets rid of the zero plane, I find it annoying..
Set a scan Y value of the length of your object to be scanned, you can remove the block anytime after cal'ing, but dont change Z height after calibrating..
Pressing Scan will now generate a point cloud called points.txt inthe mach3 folder. Youll find rhino has no trouble loading it. The demo of rhino is good for
25 saves, so as long as you dont save, you can view all the point clouds you like..
The samples setting is a averaging setting, the higher it is, the longer the scan will take. The Y stepover is the amount the camera will move on each scan.
Play, have fun, post any cool clouds here so we can all see them.. Ill post updates as I continue to make things more robust,
I can tell you laser probing is more of an Art than a Science.. ( no pun intended.
)
Ive made quite a few cool scans lately, much work remains to be done to clean things up before I start to try meshing it all to a
3d model file, but I think a few woudl like to play with the clouds, and its all pretty easy to get used to really..
God luck,
Have fun,
Heres the plugin..
Art
Having lights on makes it very hard to reject specular noise. Youll also notice there is a raised section to the laser line. Thats beacuse there
is a 52mm block of wood on the table. This is the second step to starting up. When YOU start, have nothing in the field. Rotate your laser do the red line in the second
image is as straigth as possible. Then insert the block off wood or obejct to calibrate with., I use a simpel wooden block measured at 52mm high and 52mm wide. width doesnt really
matter, but you want to make sure the line below the block is showing well as well as the line on the block.
The slider between the images is a threshhold. Slide it up and down until you have what looks like a square wave on the line monitor window.
The White line incidently is raw data, the red line is CenterOFMass corrected, and centroided to produce a cleaner line. Lasers can create noisy lines.. so the red line is the
cleaned line. Leave all the numbers alone except for the Cube size, enter the size of your block there. (inches or mm's shoudlnt matter, whatever mode Mach3 is in..)
Then slide the threshold slider for a good square wave so it seems to be sensitive to the edges of the block but with as little noise as you can get, but make sure the
width of the block appears to be seen. Then hit calibrate. Repeatedly hitting calibrate, you should see now the laser angle showing and perhaps varying about .1 degrees, it
may vary more, ( or less) depending on the camera, and the laser. Not too important in organic scanning, but the more accurate is it, the better.. The camera height should now
show pretty close to how high the cameras focal plane actually is..
On the point control, you can see its set to reject any Z's less than 1mm, this just gets rid of the zero plane, I find it annoying..
Set a scan Y value of the length of your object to be scanned, you can remove the block anytime after cal'ing, but dont change Z height after calibrating..
Pressing Scan will now generate a point cloud called points.txt inthe mach3 folder. Youll find rhino has no trouble loading it. The demo of rhino is good for
25 saves, so as long as you dont save, you can view all the point clouds you like..
The samples setting is a averaging setting, the higher it is, the longer the scan will take. The Y stepover is the amount the camera will move on each scan.
Play, have fun, post any cool clouds here so we can all see them.. Ill post updates as I continue to make things more robust,
I can tell you laser probing is more of an Art than a Science.. ( no pun intended.
)Ive made quite a few cool scans lately, much work remains to be done to clean things up before I start to try meshing it all to a
3d model file, but I think a few woudl like to play with the clouds, and its all pretty easy to get used to really..
God luck,
Have fun,
Heres the plugin..
Art