I'm working on some small parts, and I noticed a difference between what the part looked like in my CAD application/Netfabb, and the rendering that was generated when I uploaded the part. 'Part in Netfabb' shows what I've designed. The surface is smooth: 'Shapeways import' is a screenshot of the product upload page. Note the rough surface: Initially I thought it might be a problem with the STL export from Netfabb, but when I re-import the STL into Netfabb it still looks smooth. Same when I import the STL in Meshlab. Stranger still, I've uploaded several versions of this part. Some are rendered smooth, others are rough, but I haven't changed any settings between uploads. The uploaded part is here I've attached the STL.
That is caused by the underlying technology in the new renderer. As good/fast as the new renderer is, it will always have this "problem". The new renderer uses "Voxels" instead of "Triangles" when building the image, and the image it builds is a bit lower resolution than your actual model is. The full-resolution model will be sent to the printer, and you (should) not see such artifacts in the final print.
Ah, I see. I was worried that my STL was being converted after the upload, but if it's a display issue only I can live with it.
where is this screenshot from, the wallthickness visualization or the thumbnail? The wallthickness viz is voxelized. Your model is not and so the thumbnail we render should not show those artifacts.
But it's good... I believe stony is correct, that the 'Edit Model' voxel issue (whatever they are!) is the cause. I would be very surprised if the yet to be released wall thickness visualisation image and the 'Edit Model' view were not based on the same tech. My experience is that the boring old shop renders (static and 3d) give pretty good indications of what will be printed. Of course you have to take into account the size of the model and the resolution of the printer, but that being said, these images work for me.
@Hobbes010: One unrelated question: what browser are you using? I seem to be unable to zoom in that close to my models when using that 3d viewer.
I'm using Firefox. Zooming only works on the 'Edit Model' page. If you're on the shop page, you can't zoom.
That are Lighting artifacts. Normally the most renderes smooth the surface using interpolate normals. Shapeways rederer do this not. This has a reason: If the rederer would smooth the round objects, the costumer do not see on the preview, what he really gets. The rendering looks smooth but the object is very lowpoly and faceted. This problem you have is has other models to. http://shpws.me/oN1W Yo can see it on the knob. Your model is extreme. It do not affect the printing it just looks ugly. At the moment i have tot full understand witch causes the problem or how to avoid it.
I would be very much surprised if Netfabb did this. The model as shown in Netfabb matches my design exactly, there are no extra surfaces compared to my original CAD model. A low-resolution rendering would explain the difference, basically you get rounding errors in the position of each pixel.
That's a remeshing of the original mesh, not just lighting artifacts. He shows a different face layout in the green renders, with lighting artifacts that don't match the grey ones. http://en.wikipedia.org/wiki/Marching_cubes
? There is not realy a face layout in the green redering visible. If I download the STL an view the mesh I find the characteristics of the mesh in both images. anyway the conclusion is, these are ugly artifacts an not affecting the print.