topic Display detail control broken? in Fusion Design, Validate & Document Forum

Display detail control broken?

sambeck2325 — Sun, 20 Mar 2022 09:31:52 GMT

Hey guys,

I've noticed there seems to be a problem with my most complex part in my model. The rest of the bodies seem to be rendering as expected and have a sufficient amount of polygons. But the main part that holds everything together is showing up really low quality and the "display detail control" which did previously work to make a difference when changing it's value has stopped doing anything all together, no visible difference when flipping between low/med/high. In the screenshot below you can see the sphere object with a hole is smooth and fine, but the outer object is all janky looking. Any thoughts? I would love to have a lot more control and insight about these "detail controls" I want to be able to look at the polygon wireframe and decide exactly how much detail I am getting before a render for instance. Need some help! Cheers.

Re: Display detail control broken?

jeff_strater — Sun, 20 Mar 2022 13:57:31 GMT

Please share this model here so we can investigate. Cannot tell much without the model. I do know that Display Detail Control has not changed in years, so I suspect this may be particular to this model.

Re: Display detail control broken?

sambeck2325 — Mon, 21 Mar 2022 07:32:14 GMT

@jeff_strater Sorry, was hoping this was something simple.. here you go https://a360.co/3N3fsrU

Edit: the body in question is "Main Hull", keep in mind this model is for rendering purposes, so it may not be built very well. I have learned a lot as I worked and would probably do things a lot differently on a second time around.

Re: Display detail control broken?

sambeck2325 — Mon, 21 Mar 2022 07:54:04 GMT

I tried the offset surface command and found it interesting that the result is smooth but the original surface isnt. not sure if its helpful or not.

Edit: Another observation is that I loaded this up on another computer and there was no difference. This is troubling because I was planning to use the model in a keyshot render in the near future (I have no idea, yet, how to use keyshot and don't have a license for it yet.. so cant test if this problem persists in another 3d software environment, but based on the online file preview I am no so confident this will be a non-issue)

Re: Display detail control broken?

TrippyLighting — Mon, 21 Mar 2022 12:25:33 GMT

@sambeck2325 wrote:

Edit: Another observation is that I loaded this up on another computer and there was no difference. This is troubling because I was planning to use the model in a keyshot render in the near future (I have no idea, yet, how to use keyshot and don't have a license for it yet.. so cant test if this problem persists in another 3d software environment, but based on the online file preview I am no so confident this will be a non-issue)

The faceting you are seeing is entirely a viewport rendering issue. The actual NURBS/BRep geometry does not exhibit that problem, unless you are working with a triangulated mesh model, which I don't think is the case here.

With Keyshot's plugin you should not have this problem. All models, regardless of what render engine/software you use go through a meshing stage before they are rendered. Keyshot has its own mesh converter and does not need to rely on the specific CAD software.

Unless you already own Keyshot I'd test this before committing to a purchase!

Re: Display detail control broken?

TrippyLighting — Mon, 21 Mar 2022 13:03:49 GMT

Super nice model!

Re: Display detail control broken?

jeff_strater — Mon, 21 Mar 2022 17:04:18 GMT

Thanks for the model, @sambeck2325 (I agree with @TrippyLighting, very impressive model here).

I think what we are seeing here are the limits of Display Detail Control. It acts on the entire body. Faceting itself is also done on the entire body. What we have is a relatively small feature, on a rather large body:

and because the analysis is done globally on that large body, the smaller features suffer. Since Display Detail Control only has 3 choices, even High suffers this problem. This is also why the offset surface looks so nice - it is its own body. What is really needed is either more local control of facet precision in areas of a body, or even more control for the entire body. Save as mesh is basically the same process, and there are lots more controls there:

However, even with those controls, the faceting is still done body-wide, so you end up with a pretty dense mesh in areas where it is not necessary, which is likely to be slow to create, and heavy in terms of memory footprint (the graphics facets are not saved with the model, so it does not affect model size, other than memory when opened)

Re: Display detail control broken?

sambeck2325 — Wed, 06 Apr 2022 06:25:37 GMT

BOOYAH! I have found myself a solution. I feel like a genius, not gonna lie.

So after learning the NURBS data was essentially intact, I figured I needed to make it easier for the software to render all of the data "at once". I created a cylindrical surface in the center of the hull where I could create a relatively uncomplicated split in the body. My theory was I could essentially shear off a bunch of the nurbs data by making a bunch of cuts around the hull. To my amazement, after the first cut the entire hull decided to render properly. However, the arguably more simple of the two new bodies, the area inside the circle, was still afflicted by the low res mesh geometry. Out of curiosity, I decided to split the new circular body down the middle (a perfectly symmetrical cut), to see if the issue would "Pick a side".... and it did.

Now the issue was isolated to this left side. I thought it was peculiar. Surely, this is not some drawback to the limitations of the software, as in, I don't think I'm pushing the limits with this left side as it is clearly working fine over on the right. So! This is where I bust out the moves. I create a mirror image of the GOOD side. "Hide" the bad side. I then have two perfectly rendering bodies, so I decided to join them together, and boom! Now there was no visible geometry affected by the low res mesh.

Sweet success..

Interesting bonus glitch though:

The "bad" side, no longer renders at all!!! Luckily the joined version of the good side is rendering fine.

Crazy stuff!