end cap lofting, not very smooth

[eric_strebel]

I am lofting the end cap to a simple 4x6 stamped part. However, I don't seem to be able to make the transition very smooth, even thought I have smooth selected. Any ideas??

Perhaps I am missing something here??

[keqingsong]

Could be a graphics bug...go to Analysis and apply the Zebra analysis to this body. Share a screenshot of it with the Zebra analysis turned on. Do you see any dis-continuity (stripes being abruptly jagged at that edge)?

[eric_strebel]

Yes, my goodness, it's horrendous! probably not a graphics card issue. I can give you access to the file if you would like to have a look.

[keqingsong]

hmmm interesting, okay that's good to know. Yes, please share it with me! 

[eric_strebel]

private message me your email address to share.

Thanks

[keqingsong]

Is there a reason why your center construction line is slightly lower than your actual center line that you used to loft? 

[eric_strebel]

Hmm, no not necessarily. Would have to look at it. The concruction line is meerly a guide. Is that where I have made an error?

[Anonymous]

Hey Eric, the following thread has examples of how to get very good results with this kind of shape:

http://forums.autodesk.com/t5/design-and-documentation/how-to-solve-this-in-fusion-half-rounded-cap/...

Take a look at the .f3d model files, and let me know if you have any questions about them.

Good luck!

Jesse

[eric_strebel]

@keqingsong Do you have a solution for me yet? adjusting that line did nothing...Hopeing to get this sorted out soon. Any ideas why this is not working?

[cekuhnen]

So Fusions surfacing tools show in this case their clear weakness.

The codes cannot deliver the same surface Alias would do. I spend an hour trying to trouble shoot Erics shape till I gave up and decided to use an old school trick.

Even that one failed because of edge issues.

So the combination of old school hacks and helping with some rails can do the trick.

Watch the video:

https://drive.google.com/a/ckbrd.de/file/d/0Byzv_NlyKp_2OWM4VmlhVy1nTTA/view?usp=drivesdk

I hope that next year with advanced surfacing those deficiancies will be tackled.

[cekuhnen]

@keqingsong Simple serious designers do not use G1 at all - that is for beginners or those who cannot model better 😉

The orange arcs are perfect circle references but the blue curves are sketches with smooth constraint added.

With G1 you would just get the typical G1 highlight breaks which are not desirable.

[cekuhnen · Accepted solution]

@eric_strebel  Since the Autodesk tech support dropped the ball here and left you alone with the problem I applied a technique from surfacing to solve this surfacing issue:

>> I used solid mode because solid lofts does not have the edge issues patch loft has! <<

You make a normal sphere based (revolve tool) half cap

Mirror it

Loft between them

cut a decent part out of the linear and cap part

and solid loft with smooth to rebuild the transition

The trick is to make the opening wide enough so that the secondary sufrace (blend) is nice and smooth giving you good highlights

Here is a link to the gif:

https://drive.google.com/open?id=0Byzv_NlyKp_2aHo2V1dOUEF2V0E

[eric_strebel]

Thank you @cekuhnen for you help since I got left out in the cold on this one!!!!!!!!!!!!!!!!!!!!!!  I must say I am dissapointed that nothing was done to assist me from Autdesk. I was hopoing @keqingsong was going to reply to my posts.....No luck with that. I think some sort of acknoledgement would be the right thing to do here.

Here is the final surface that was created.

[cekuhnen]

ah the zerba looks good

[keqingsong]

@eric_strebel Very glad to see that @cekuhnen and @Anonymous was able to help you resolve this issue. I was keeping an eye on this thread and did not jump in time to acknowledge the fact that what @cekuhnen showed in his video was the right thing to do. Our loft tools are still not complete, hence why you were getting the abrupt edges in your first workflow. 

Cheers, 

[eric_strebel]

@keqingsong well....you left me hanging for almost a week! Yes, I am dissapointed. if you know that, then you need to say something at the beginning of the tread. and atleast offer a work around or some options. No offense, but, people post stuff here for assitance, not replying does not help. It just so happens that @cekuhnen is a friend, and he was gracious enough to help. Had that not been the case, I feel I would still be in the same situation. I am hoping for better next time.

[keqingsong]

@eric_strebel, apologies for not getting back to you sooner. My intent was definitely not to leave you hanging. As the thread evolved, I wasn't aware that you were still waiting for my response after Claas and Jesse responded, providing you a reasonable work-around to get the shape more consistent. I assumed that you had accepted their solution since Claas and Jesse are both very knowledgeable, and in some cases (like this one), more knowledgeable in Lofting than I am. Their expert knowledge, combined with other Fusion 360 expert elites', yours, and all our other engaged members is what allows our forum to continue to thrive as a community of users helping each other.  

[cekuhnen]

@keqingsong It would have been good to know that there is an issue with the code when lofting such shapes.

Knowing this sooner would have helped to quicker solve this issue and not spend so much time on attempts that ultimately faild till I did the old Rhino trick.

The workaround works but is not really ideal. It is an old Rhino hack because Rhino is still prone for being poor with fillets.

Cannot wait till next year when Colin's advanced surface tools materialize.

[gautham_kattethota]

Hi Eric,

I read that your issue has been resolved, but I am interested to see why the loft did not produce a desirable solution in your case.  Could you post your original file on this thread or email it to me at kattetg@autodesk.com.

Thanks
Gautham

[cekuhnen]

@gautham_kattethotaI send you two files showing the problem loft has when used like a sweep rail like command.

The sweep and loft commands in Fusion try to work like those in surfacing apps but dont really deliver the same result

and quality surface.