This is maybe a feature request but also may just be me not understanding what happens when I open a file in Nomad.
I designed a structure in nomad & re-modelled it more accurately in other software. I reimported it back to Nomad to continue developing and adding to the model. As the objects are hard edged, my initial import resulted in smoothed edges where I expected to see hard edges. I remembered the “Keep topology on import” check box & tried that before I reimported. Everything came in squared off with nice hard edges. All of the images below are rendered with smooth-shading turned on in the display settings.
I continued working on the model, adding geometry but nothing further to the structure (which was squared off at this time). I made several saves along the way and closed Nomad when I’d finished working. Upon reopening Nomad and the file to continue working I noticed that the previously squared off edges had been smoothed.
What I’ve discovered following several tests is that if I save the imported squared off geometry then I need to open Nomad, select “Keep topology on import” and only then am I able to open the Saved Nomad file and retain the un-smoothed version of the geometry.
Long story short - is this expected behaviour following saving of imported geometries or is this a bug? Now I know how to work around this issue I know that I need to click on Keep Topology before opening the file, but can see that this sort of issue may hinder others in the future.
Images attached show the different ways my model is displaying. Again, all of these images were exported with Smooth Shading checked to On in the display settings - which is required to show the additional curved geometries that I wish to add to the model.
I guess it’s the general Nomad smoothing algorithm.
In 3Ds Max I would add a smooth modifier and use Auto smooth with default angle set on 45 degrees.
I was surprised your model was displayed like in first pictures at all!
Did you achieve hard surface look in Nomad with smooth shaded active and without flat subdivisions?
Trying that in Nomad only, I had to check flat subdivision and add one, better two subdivisions for sharp edges.
The model is not subdivided at all, which is probably where Nomad is finding difficulty. I could only keep the edges sharp by ticking the experimental “Keep topology on import” in the Display settings - the tooltip says to use this to stop Nomad from fiddling with the geometry so I thought I’d give it a go. It works but not when you open the saved file without choosing keep topology (even though it’s not importing that time, it;’s just opening the saved Nomad file format).
I couldn’t get the model to sub-divide sharp enough to look good, which is why I had the idea to try the “experimental” import setting. The problem is really that you can’t leave the box ticked for that setting as it is not saved when Nomad is closed.
When keep topology at import is disabled:
- Remove unused vertices (not used by any face)
- Remove/clean degenerated faces
- Merge duplicated vertices
- Remove duplicated faces
Smooth edges are probably caused by 3.
Note that 3. doesn’t use any threshold, the positions needs to be strictly equal.
My file is OBJ exported from Revit (CAD) and may therefore have double sided faces as part of the export - I’ve had issues with this when importing to blender as OBJ, but there are no export settings so I use other formats for blender. I may find a workflow of putting the model through blender to work better.
Strangest thing to me is that I still have an un-smoothed Nomad file that stays that way as long as I keep the experimental checkbox ticked. I thought that was only for import or does it refer to anytime you open a file?
Isn’t it the general use of smoothing in Nomad?
As I understand one can switch it OFF. Nothing is smoothed.
Or ON and everything is smoothed.
If one could enter a value for a degree, when polys are smoothed or displayed as hardsurface, this would solve above issue.
But it would slow down Nomad too much, wouldn’t it?
Yes, anything that loads a file.