Tom, I am flattered! 
But that was still early-ish on in my learning process.
Also a bit of luck maybe?
Plus nicely textured walls, the white areas are almost devoid of tie points - which is causing most of your difficulties I believe…
Wow looka that - first time I’ve effortlesly got a result like a veteran! Well, after doubling the no of photos by blasting the corners where the Components wouldn’t join up. Though I bet if I deleted that Component and Aligned again it wd go back to 2 or 3 Components.
That’s one room done, all walls - now the other one, then the look-both-ways through the doorway.
I said to Gotz: “in Inspect - you still say that dark blue means less connections, light blue/green more, yellow/orange more again, cerise, then red the most connections?”
Gotz answered: “Yes, the color coding has been explained a few times by Devs and I thought it is also in the help”
which leaves me puzzled - ‘blue = weak, red = best’ doesn’t agree with what happens when I tweak Inspect settings. So I’m collecting votes - which way it really is - and it’s contradictory.
In https://support.capturingreality.com/hc/en-us/articles/115001552532-Quality-assessment : “A web of blue lines should appear. The colour scale of the Inspection tool is blue to red. The more red, the worse. On the other hand, the closer to blue colour, the better.”
Zuzanna in https://support.capturingreality.com/hc/en-us/community/posts/360001888972-Border-between-areas-with-differing-distances-of-the-cameras-to-the-object says: “The edge color is blue-to-red (Jet color scale) indicating how strong an edge is - actually more features, more red.”
Not trying to smart-■■■■ - just want to get things clear, so’s to actually intelligently use the huge amount of precise data that RC delivers - if only they’d explain (better than in Help) what things mean.
Blue is best connection, red is worst. Anything between is average.
Thank you greatly.
Sorry to disagree, but in the help it clearly states:
“The edge color is blue-to-red indicating how strong an edge is - more features, more red.”
More features is commonly associated with better.
RC staff, if you’re reading this, there seems to be a contradictory/inconsistency in what RC people publish. Evenly divided.
e.g. Help contradicts https://support.capturingreality.com/hc/en-us/articles/115001552532-Quality-assessment .
What is the double-checked true answer?
Tom, I think that either the content in the you provided is wrong, or I really miss the point entirely.
Just try it out. If you set the Maximal Matches to, say, 1000, all of a sudden you have plenty of red lines and more cyan, green and yellow as well. The value defines the saturation point for red, 1000 tie points between two images. Play around with the number and you’ll see. Blue is the only colour that connects images far apart, which stronlgy indicates that those are weaker connections.
What I haven’t figured out is the difference between Matches Count and Minimal Matches. Maybe somebody is willing to shed some light on that. Is Matches count basically a filter for images that have fewer overall tie points than the threshold?
Hello guys,
Thank you very much for bringing up this issue. It is the best way how we can find out that we need to make the help section clearer about this feature. We are sorry for the misleading information and inconsistency.
The full and correct extent of answer is as stated in the RC App Help. „The edge color is blue-to-red indicating how strong an edge is - more features, more red.“ is correct. If the edge is red, it means that it is the strongest one.
We will correct the information in the Quality assessment tutorial and we will also try to improve the description of this tool in the application Help.
To answer the Gӧtz’s question about the difference between Minimal matches and Matches count, this is how it should work:
Matches count and Component connectivity define how the cameras are connected into virtual components.
Component connectivity –from Help section – “Every two different components would have less (component connectivity) edges in-between.” If there are at least this number edges between cameras, then those cameras are connected into one component (two components are not created).
Matches count – two cameras are connected into one component only if there are at least this number of common features (matches) among those two cameras. Those features however have to suffice the condition defined by apical angle and Feature consistency.
Minimal matches – edges with the number of features lower that this value are not displayed at all. Edge with this number of features is displayed with dark blue color.
Maximal matches – if set to zero, all edges are displayed. The edge with the highest number of features is displayed with dark red color. If you set the specific value, then it is the greatest number of connections between two images. Color scale is recomputed accordingly to minimal and maximal matches.
The most important thing to check with Inspect tool is the number of created virtual components with the component connectivity set to at least 4. This means that if the images are connected into one virtual component with the component connectivity set to at least 4 (that is the reason why the default value is 4), the alignment can be considered as stable and no cracks or misalignments should appear. If there are several virtual components created than the connection among the cameras from these separate components is not that stable and we would recommend to add images in these areas.
Hi Zuzana,
thanks a lot for the extensive answer!
I read the help section today of course…
I think I got it now. Matches Count defines the basis for the calculation and Minimal Matches caps only the display of the result. So if Matches Count is set to 50 but Minimal Matches remains 100, then the display won’t change.
Concerning Maximal Count: I think it’s important to mention that the value will not result in fewer lines, just move the color threshold for red down to this number. That means all image pairs with more than e.g. 1000 matches will also be red.
So Connectivity means how many “partners” each camera has?
Also, is it correct to assume that if Maximal Count is left blank, red will be the connection with the most tie points in this model?
Bingo! some real intelligible discussion on the subject (starting with Gotz’ “Just try it out”). Will take some careful reading.
I think its a bit missleading because red means most of the time error or failue, perhaps rename the button to „inspect connection heatmap“ and its all fine, red high temperature, blue cold low temperature.
Great thread!
“red means most of the time error or failue”
I’d love to know how you know that?
I mean, in general just ignore my comment.
Zuzana said:
“The most important thing to check with Inspect tool is the number of created virtual components with the component connectivity set to at least 4. This means that if the images are connected into one virtual component with the component connectivity set to at least 4 (that is the reason why the default value is 4), the alignment can be considered as stable and no cracks or misalignments should appear.”
This is very good, useable advice. So even if in Alignment all or nearly all photos have registered into a single Component, if in Inspect it’s still split into several ‘Virtual Components’, it’s still not a robust Alignment? and needs more photos.
(It’s really unfortunate, two completely different uses of the word Component - and so close together in the process. Confusion guaranteed?)
Now, I can fiddle this. I can get all cameras into one single Virtual Component, “with the component connectivity set to at least 4”, without adding photos but simply by reducing Matches count: “Matches count – two cameras are connected into one component only if there are at least this number of common features (matches) among those two cameras.” I reduce default Matches count from 100 to 49 and suddenly it turns out that sufficient camera pairs have at least 50 matches, and so all can unify into a single Virtual Component (and a couple of detached solos).
Of course, this fiddle doesn’t change Alignment at all, is just a way of Inspecting it.
But just as it’s important that single Virtual component is achieved @ default Component connectivity 4, how important is it @ default Matches count 100?
Zuzana said:
“If there are several virtual components … we would recommend to add images in these areas.”
With multiple Virtual components, the different camera colours aren’t distinct enough to get a mental image. I assume that’s how I should decide where are “these areas” that I should add photos? What am I looking for? I’m seeing no gaps between virtual Components - they are intermingled.
Also it’s very hard to count the multiple Virtual components, by hovering the mouse to see what highlights - or is that not useful anyway?
Thanks a bundle, both Zuzana and Gotz - makes a huge difference.
But still missing for me is Feature consistenncy and Apical angle - “Those features however have to suffice the condition defined by apical angle and Feature consistency.”
Also Internal vs External edges vs Both?
Hello everyone,
„Concerning Maximal Count: I think it’s important to mention that the value will not result in fewer lines, just move the color threshold for red down to this number. That means all image pairs with more than e.g. 1000 matches will also be red.“
Changing Maximal Count value can result in fewer lines and also the color scale is recomputed. You can see the illustration in the picture below.
„So Connectivity means how many “partners” each camera has?“
If one camera has less connections with the cameras in the virtual component, it is not included in this component. If the camera has let’s say max. 2 connections with the cameras inside one virtual component and the component connectivity is set to 3, then this camera is not attached to the component.
“Also, is it correct to assume that if Maximal Count is left blank, red will be the connection with the most tie points in this model?”
Yes, it is correct.
„But just as it’s important that single Virtual component is achieved @ default Component connectivity 4, how important is it @ default Matches count 100?“
Edge within one component has to have at least this number of matches. RC takes a feature, if this feature is visible in defined number of images (Feature consistency) and if the angle among the pairs of cameras is bigger than the angle defined by Apical angle, the matches count for the edge is raised by one. Matches are the features that suffice these two conditions.
You can also analyze only selection of images if the Analyze selection is set to ‘True’. You do not need to actually count the components, you need to see if there are gaps among them or if there are separate virtual components in any part of the model.
“Also Internal vs External edges vs Both?”
Internal edges are the edges inside the components, External edges are the edges outside components, the ones connecting individual components. If you use both, then you can see all the created edges (the grey ones are internal, the colored ones are external).
Dear Zuzana,
again, thanks a lot for the answer! I apprecitate the recent activity of you guys at RC very much.
Hmm, ok, so no lines above the Maximal Count threshold. Good to know. Would it not makes sense to add another variable where one can simply define the point from which on all the lines will be red? Because that would have the advantage that the color range can be made more useful (usually most lines are blue) without losing some vital information.
>>„So Connectivity means how many “partners” each camera has?“
If one camera has less connections with the cameras in the virtual component, it is not included in this component. If the camera has let’s say max. 2 connections with the cameras inside one virtual component and the component connectivity is set to 3, then this camera is not attached to the component.<<
So the short answer to this question is also yes? Or did I miss something?