Answered
setting bitmap image rotation scale and datum
Hi Group
See the image of a ruler below. In Rhino 3D, I can rotate this so the ruler is straight / horizontal to my screen, then I can scale it to the correct size in mm’s using the ruler as a guide and I can set a datum to the top left corner of the steel rule.
I use rulers in image scans for exactly this reason, once I have set the scale and position of the scan I can then trace around the objects for a DXF file output.
Can I do this in Carveco?
I seem to only be able to rotate in 90 degree steps.
Comments
As far as I know, you can only rotate by using the Bitmap > Deskew tool. It doesn't give you the control you are looking for, but it certainly does allow you to rotate it precisely. If you measure the angle with the tape measure tool (or polyline, then measure) you can get fairly close to where you need to be.
However...I've found that you get a lot more control and better results if you pre-process the image using a free image editor like GIMP. GIMP lets you drag the rotation center to say the upper-left corner of the ruler, and then pull down a guideline (just like Carveco) to set a horizontal reference. You can then use the controls to find the precise angle of rotation to get the image aligned.
Hi Brady
Thankyou for your reply, if I was able to rotate in another package and bring into carveco how do I then scale the image to correct size from a point in the image?
Also I am not keen on editing the image as such just in case it gets distorted / changed accidentally
I think this would be a good development feature in Carveco. I trace a lot of images. However, I did find a post in an old ArtCAM Forum that was very similar and it was said then it would be a good upgrade by a moderator?
Adrian Walker wrote: "I think this would be a good development feature in Carveco. I trace a lot of images. However, I did find a post in an old ArtCAM Forum that was very similar and it was said then it would be a good upgrade by a moderator?"
Please provide a link to the ArtCAM Forum post you're referring to so that we can review it.
A comment confirming something as a good idea does not necessarily mean that it makes its way to the software development roadmap. Furthermore, Carveco will not be following any past roadmap associated with ArtCAM software, which is now a discontinued product.
The Feature Requests topic gives the community a plarform to put forward their ideas and suggestions regarding Carveco software, and you're most welcome to post there.
Hi Adrian,
I also do a lot of digitizing of images and my workflow has been to rotate the image precisely in an image editor and either scale it there (GIMP will do it all...and it's free) or, just pull it into Carveco and go ahead and trace out your vectors. Once you have it vectorized, you can precisely scale it using the Transform Tool. Since it is now a vector, it will be correct.
One method for scaling is to draw a single straight polyline between points that you know the exact distance of - but make it perfectly horizontal or vertical so it has length but no width or vice versa. Then, measure that line. Take this measurement and divide it by the actual measurement so you have a percentage. Then using the Transform Tool, scale all the other vectors to that same percentage & everything should be to scale.
Of course there are caveats with photogrammetry...I use a DSLR with a calibrated lens and lens profile (DxO Viewpoint) because lens distortion can really mess up your measurements & has to be compensated for. A cell phone camera just doesn't cut it for real work.
Yes, of course this would be a great feature to have in Carveco, but...in the meantime there are other ways to get there...
Here's the link: https://forums.autodesk.com/t5/artcam-forum/image-scaling-and-resizing-in-artcam-standard/td-p/7534624
Autodesk comment at the end, but I am aware that ideas don't make the final cut especially with Autodesk :-)
However, I think it would be a real asset ;-)
Hi Brady,
Thank you for your reply. I use Photogrammetry as well with a calibrated SLR camera and targets etc. I use Photomodeler and I understand the distortion and perspective issues. However, this image of a ruler is actually scanned which does not have these issues so is plenty accurate enough to use for these purposes.
In a few cases, accuracy is very important. As in this case, I am working from an old bronze sign and I am modifying it so tolerances are very tight and need to be as close as possible.
I will try out your suggestions to see if it works for me.
Hi Brady,
The Gimp software is good and I am playing with it now; I have rotation sorted.
When back in Carveco and using the Transform tool like you have said, will transform the vectors but not the background image?
One issue I have had on machines is that if you scale vectors like this you can end up with many thousands of lines and arcs and machines don't like this. I like to trace items in CAD so that there are minimal lines and arcs and never use beizier curves as these end up in many lines and arcs on the machines.
This is why I would like to get the picture the right scale in Carveco to work from, as then I will be working from actual data.
Adrian Walker wrote: "When back in Carveco and using the Transform tool like you have said will transform the vectors but not the background image?"
No; select your vector followed by the Model > Set Size menu option, select the Set Model Size dialog's Selected vectors option, then specify your required Height or Width. The image is then resized using the selected vector.
Gary
thanks Gary that works :-)
I am starting to get the results i need. If i need to rotate during vectorisation, is it possible to deskew the image and rotate the vectors already placed at the same time?
i.e so it all rotates together?
Adrian Walker wrote: "If I need to rotate during vectorisation, is it possible to deskew the image and rotate the vectors already placed at the same time?"
No, you cannot deskew a bitmap image in unison with transforming a selected vector.
Adrian,
When I said vectorize, I meant to manually trace out the bitmap using a polyline. Bitmap to vector utilities for the most part give less than desirable results on photographs. Rough out with polyline, then node edit as required.
After you have traced out, you need to scale it. This is where I mentioned the horiz/vert vector and using scale percentage via the Transform Tool. When I do 2D digitizing I don't even think about scale until I have the vectors exactly where I want them on the photo.
Thanks Brady.
The reason I like to trace at 1-1 scale is because I like to keep lines and arcs/nodes to the absolute minimum, especially if we are going to waterjet cut a design as the machine doesn't like lots of lines and arcs in the software it uses.
Adrian,
Everyone works a little differently in the software. I say the way that makes the most sense to you & that works - is the 'right' way! :)
Here's one way I would do it:
https://www.youtube.com/watch?v=A1NV7uY13Qg&feature=youtu.be
Brady,
That is way cool.
thanks
mike
Thank you Brady
that explains the process well :-)
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