Weird surface after making holes

[jpbaehr13]

Hello,

I have been dealing with this issue on this particular model. After extruding holes, a weird surface becomes noticeable.

It even appears when I export as STL 

Any suggestions?

[Drewpan]

Hi,

Does this happen when you have default appearance or material settings? It may be the rendering of the material

with the holes you put in and probably not a major issue. Fusion sometimes struggles to render properly with different

shapes and certain appearances. Does it make a difference when you extrude the holes in groups? That may fix the

problem also as it reduces the amount of calculations.

What does it actually look like if you run a Render on it?

Cheers

Andrew

[jeff_strater]

This seems like a faceting issue.  Try changing the display detail control on that body:

Choose "fixed", and try changing to one of the choices (low, med, high).  Sometimes that can have an effect.

[jpbaehr13]

Tried that, didn't seem to make much of a difference. Still have many distortions

[jpbaehr13]

I removed all appearance related effects, still getting the issue. Also my holes are all in separate groups, it appears right from the start of my model after extruding.

I am going to try and remodel and see if it continues 

[jpbaehr13]

Also, this does indeed change the result of the exported STL. Here is an example of the original model, versus a early version that does not have as many features. In these pictures, I imported the STLs into VCarve, to be manufactured on a CNC. 

[laughingcreek]

can you export your model as an .f3d and attach. would be good to get to the root cause of the problem.

[jpbaehr13]

Yes, here you go.

Here is a copy of the model with some features removed, but still the same issue nonetheless

[laughingcreek]

the problem seems to be related to the sketch.  is this an imported svg? (or some other import format?)

[jpbaehr13]

I imported a picture to the canvas but the sketch is made by myself. 

In order to create the holes, I used the pattern on path

[jeff_strater]

I don't think this is the sketch (other than there are lots of holes defined in the sketch...).  This looks to me like a classic faceting problem.  It shows up in a mesh export (STL) because conversion to mesh uses the same faceter as is used for the graphics generation.  Changing the display detail does help (on the sample here).  If I set it to Medium, it is better, but there still is at least one hole that is not right.

default:

Medium:

The rest of my usual techniques (splitting the face) don't seem to help here.  FWIW, we are working on a new faceter implementation, I've asked the team to try it on this model.  We hope to be releasing it soon, but I don't know when that is, sorry.

[jpbaehr13]

Thank you for the insight, incredible that I am speaking to an Autodesk employee. 

Love your products and good luck with the implementation of this solution

Look forward to seeing an update

[MichaelT_123 · Accepted solution]

Hi Mr Jpbaehr13,

The surface artefacts are created when the rendering engine processes the coplanar surfaces. The graphics calculation path involves triangulation of surfaces and shading them (applying an appearance). In the process, input data precision reduction and changing calculation domain from real numbers to integers make the whole process fast and resource-efficient. Along the way, the necessary rounding's will go two ways, and the effect will be seen as the image artefact, which is when two or more tessellated triangles are almost coplanar.

It is a very rough explanation.

Go back to the real story.

The removed half-tree still resides in the design ... but it is hidden. Removing means in the F360 context ... hide. The actual object data can not be REMOVED ... because it supports all the children objects derived from it.

So, after upgrading our conciseness, we can streamline the chop-chop process and still have a happy whistle time … but with a touch more thinking.  

The simplified file is attached.

In the context of the problem ... Tree (F360) was not a villain ... the chopper was!

WARNING:

I modified the sketch a little ... thus repeat the above process yourself to make sure that all is right!

Regards

MichaelT

[jeff_strater]

I know that this does not help, but we did test your model on the new faceter, and it works really well:

Note, this tool shows the actual facet boundaries - it will not look like this in Fusion, once this faceter is integrated

[jpbaehr13]

Thank you for giving an update! I look forward to seeing it rolled out in
an update 🙂