Hi Guys , I’m want scan a object of smooth & Non-Color Surface , i got below two issue , can any expert tell me what’s wrong and how should i do to make it right .
Problem 1.
I draw some color line onto this object’s surface , and using black background , i shoot 83 of them , but when i alignment these images in RC , it only show 3 component ( each component only has 2~3 images in it) , seems these color lines i draw onto this object does not help align successfully ? Why ?
Problem 2.
When i attach a paper Board under this object , the alignment stage is workable .( why RC need this extra board for alignment even the surface got very colorful line for RC to distinct to use for alignment? )
Anyway , when alignment is Pass , i press Construct a Normal mesh , when finish ,i got this ugly & noisy object , from the picture below , you can see the Mesh seems also extract Color line i draw to the object into mesh noise ( Note : the paper board not got any Color line mesh noise , it just a flat mesh)
So , how should i do to get the perfect smooth surface Mesh without these noisy mesh in RC ?
Well, I am not quite sure if you have shot in complete darkness or masked these images, but indeed more elements in the scene do quite help RC to tell the motion. I do believe this is being done on a turntable, instead I would recommend you to shoot in a well lit scene with a visible background and instead of shooting from single position with a turntable, you should move around the object.
Regarding your pattern you used for the surface and the noise you are experiencing, this is not anything strange. Rather than writing the things down on the object use a spray or chalk powder or whatever works for you that creates many little freckled points all around the surface, while still not covering it completely.
I shoot with black ground and two light in front of object.
for pattern i draw to the surface , you said “not anything strange” . i still not sure why my drawing cause that noise , you know some models in sketch fab also has various color in their surface , but their model detail is perfect , why my drawing to surface cause constructed mesh ugly ? how should i judge which model with kind of color in their surface should use spray for that kind of model , confuse a bit.
Here is a link to a good visual explanation of how the dusting/coating should be done in order to successfully scan a featureless/structureless object https://www.3dscanstore.com/blog/3d-scanning-reflective-objects
Please don’t take models on sketchfab as a good example as many of them have already been cleaned up/postprocessed.
whether feature or featureless , both need coating.
if I draw marker onto the surface of this object , marker will turn into mesh noise.
No, a featured structureless object would be a massive wooden table for example. It is smooth, it is polished, but yet there is a visible both big and tiny detailed pattern to be recognized as points in space. If an object does not have such pattern, the coating of very small freckles all around the object have to be applied. Markers in this case made no effect as these are huge lines instead of the tiny detail a powder, spray, dirt would make.
structure object
whether feature or featureless , no need coating.
if I draw marker onto the surface of this object , marker not turn into mesh noise ?
Structured objects such as a detail of leather or a rock or anything already tend to have enough features either structure or color pattern wise. Unless the structure is repetitive. Noise on the mesh was created because of the unpainted clean solid parts and yet the marker itself creates the same thing. Solid color with no little detail.