Close

The thread for silly Alias questions...

Postby eobet » November 6th, 2009, 5:52 pm


eobet
step three
step three
 
Posts: 189
Joined: February 4th, 2007, 7:14 am
Location: Limbo
So because of my vehicle design studies, I'm forcing myself to learn Alias (we're going to get lessons, but I don't know when, and I know I could ask my classmates, but I chose this friday evening to start, so that's why I'm turning to the internet for knowledge instead).

Let's begin (and anyone else who has similar, silly basic questions, are welcome to post here as well):

1. How do I add an edit point/CV in the midst of an existing curve?

2. When I create a new curve, or even line, I can slide the first creation point along an existing curve if "snap to curve" is enabled. But I can't seem to get this to work when using the ang command (draw a line at an angle to a curve). How do I get "snap to curve" to work on the ang command (and also, why is the behavior different than the curve/line creation... seems to me that the ang line is the one you really want to make sure is snapped to a curve properly)?

3. Keypoint curve creation seems to leave grey lines behind, even if I delete the keypoint curve. What are these grey lines and how can I get rid of them? They are very annoying, since they only seem to appear when a keypoint command is activated and they have some sort of snap behavior by default which I don't know how to turn off.

4. Keypoint curves doesn't seem to have either CVs or Edit Points. What do they have, and how do I edit them?

5. After I've created a curve on a surface, I am able to move the edit point beyond the boundaries of that surface (at which point the edit point disappears and become impossible to select). How can I select the CV when it's outside of the surface?

6. Why doesn't the "snap to point" or "snap to curve" seem to work when I move edit points of curves on surfaces?

7. How can I delete a curve on a surface? (When I use "select object" on it, which works on normal curves, the surface also gets selected, and thus deleted if I use the "delete active" command.)

Re: The thread for silly Alias questions...

Postby Sleek » November 8th, 2009, 10:43 am


Sleek
step two
step two
 
Posts: 87
Joined: October 20th, 2008, 10:27 am
That's a lot of questions, I'll just answer a couple to start the thread :

4. Keypoint curves doesn't seem to have either CVs or Edit Points. What do they have, and how do I edit them?

They have...Keypoints. You click on Palette/Keypoint curve tool box. A small sub palette appears with all the kp curves. Now use "drag keypoint" the last (9th) icon. Very handy to snap with a variety of snap to kp, curve or grid.

7. How can I delete a curve on a surface? (When I use "select object" on it, which works on normal curves, the surface also gets selected, and thus deleted if I use the "delete active" command.)

Alias has many "pick this or that" options. Go to Palette/Pick/Curve on surface (8th icon) and there you go !
Something useful : extend tool applies very well to curves on surfaces. So if a cos isn't long enough a quick fix, instead of redoing the projection/intersection that created it, is to extend it. Obviously the fragile "construction history" ability of Alias won't survive the operation.

Although I have been using Alias for some years I think I'll post one or two silly questions myself...
: )

Re: The thread for silly Alias questions...

Postby Sleek » November 8th, 2009, 3:04 pm


Sleek
step two
step two
 
Posts: 87
Joined: October 20th, 2008, 10:27 am
Yes you may ask "why then pick keypoint it not on the Pick part of the Palette ?"

Well first it not only picks but drags also. A welcomed difference with the other elements (curves, surfaces, etc..) you have to 1 select 2 choose an action to perform like move, scale, etc...Called transform in Alias lingua. Used to be called "Xform" to be sure you'll be confused.

Second reason is because I think Alias was originally developped by aliens who landed their flying saucer in Canada in the mid eighties. They were a very advanced civilization but had a logic of their own. Sadly for us the users, and more sadly for the learners.
The more visible proof of the alien origin is the "pick nothing" concept which seems...a little strange when you first try to use Alias.
And now Autodesk programmers don't dare touch the alien lines of codes to avoid them comming back (they are believed to beam programmers on their mothership and perform strange operations on them)

All the above is true and not a conspiracy theory.

Re: The thread for silly Alias questions...

Postby Cyberdemon » November 8th, 2009, 8:34 pm

User avatar

Cyberdemon
full self-realization
full self-realization
 
Posts: 3282
Joined: February 7th, 2006, 11:51 pm
Location: New York
eobet wrote:So because of my vehicle design studies, I'm forcing myself to learn Alias (we're going to get lessons, but I don't know when, and I know I could ask my classmates, but I chose this friday evening to start, so that's why I'm turning to the internet for knowledge instead).

Let's begin (and anyone else who has similar, silly basic questions, are welcome to post here as well):

1. How do I add an edit point/CV in the midst of an existing curve?

2. When I create a new curve, or even line, I can slide the first creation point along an existing curve if "snap to curve" is enabled. But I can't seem to get this to work when using the ang command (draw a line at an angle to a curve). How do I get "snap to curve" to work on the ang command (and also, why is the behavior different than the curve/line creation... seems to me that the ang line is the one you really want to make sure is snapped to a curve properly)?

3. Keypoint curve creation seems to leave grey lines behind, even if I delete the keypoint curve. What are these grey lines and how can I get rid of them? They are very annoying, since they only seem to appear when a keypoint command is activated and they have some sort of snap behavior by default which I don't know how to turn off.

4. Keypoint curves doesn't seem to have either CVs or Edit Points. What do they have, and how do I edit them?

5. After I've created a curve on a surface, I am able to move the edit point beyond the boundaries of that surface (at which point the edit point disappears and become impossible to select). How can I select the CV when it's outside of the surface?

6. Why doesn't the "snap to point" or "snap to curve" seem to work when I move edit points of curves on surfaces?

7. How can I delete a curve on a surface? (When I use "select object" on it, which works on normal curves, the surface also gets selected, and thus deleted if I use the "delete active" command.)


1: Object edit->insert will add an Edit point/Isoparm. If you actually wanted to add a CV, you could also rebuild the Curve to a higher degree using rebuild curve or the numeric boxes on the right. Theres a large discussion about the fundamentals of NURBS geometry (IE the difference between a 3 degree, 2 span curve, and a 5 degree, even though both have the same number of CV's)

3: Those are guidelines, mostly useless unless you're doing a lot of 2D construction. Delete them by going to "Delete->Guidelines" on the top bar.

5&6: I need to check this when I'm in front of the software, but you should still be able to pick the edit points of your CoS even if it extends beyond the boundry. As a general rule of thumb, I find you want to try and avoid editing CoS's directly - it is usually easier and cleaner to create a 2D curve, project it on to your surface, and then if you need to modify the COS edit the original curve (as long as the history still exists it will update). It also usually makes it easier to reference other geometry to that part by referencing the original curve rather than the COS. If you can't see the edit points just make sure that "edit points" is checked on your control box on the side so they are definitely displaying.

Re: The thread for silly Alias questions...

Postby tekbot » November 9th, 2009, 12:07 am


tekbot
 
Posts: 19
Joined: July 11th, 2005, 9:53 am
Location: New York City
1. How do I add an edit point/CV in the midst of an existing curve?
Insert works well to add an additional Edit point within a curve.
Rebuild works well to uniformly change the overall number of controls.
You can add controls to the end of a curve with CURVE EDIT > MODIFY > ADD POINTS.
overall, keep your curves simple and avoid trying to do too much with a single curve.


2. When I create a new curve, or even line, I can slide the first creation point along an existing curve if "snap to curve" is enabled. But I can't seem to get this to work when using the ang command (draw a line at an angle to a curve). How do I get "snap to curve" to work on the ang command (and also, why is the behavior different than the curve/line creation... seems to me that the ang line is the one you really want to make sure is snapped to a curve properly)?
Keypoint curves have the benefit of have some additional attributes to the curve. hit CTRL +5 to open the information window when a keypoint curve is selected. you should see a section called attributes where you can change length and a few other parameters depending on the curve. pretty handy for laying out the initial size of your object. As others mentioned, use the DRAG KEYPOINT tool to move the keypoints around. as a long time user, i only use these curves for initial layout and the perpendicular lines tool. for cars, stick with the CV and EDIT curves.

3. Keypoint curve creation seems to leave grey lines behind, even if I delete the keypoint curve. What are these grey lines and how can I get rid of them? They are very annoying, since they only seem to appear when a keypoint command is activated and they have some sort of snap behavior by default which I don't know how to turn off.
yup, those can be annoying. in the PREFERENCEES > GENERAL PREFERENCES [option box] > MODELING WINDOWS. turn guidelines to 0 to turn them off all together.

4. Keypoint curves doesn't seem to have either CVs or Edit Points. What do they have, and how do I edit them?
DRAG KEYPOINT to modify them by default. if you want to start using a keypoint curve as a typical curve you just need to turn the controls on and start modifying them. I use the control panel all the time. you can toggle CVs and EPs very easily there.

5. After I've created a curve on a surface, I am able to move the edit point beyond the boundaries of that surface (at which point the edit point disappears and become impossible to select). How can I select the CV when it's outside of the surface? Basically i would not recommend building Curve on Surfaces or COS manually. you can mess with them but they can get tricky really fast. try to always generate them with either project, intersect, or tubular offset.

6. Why doesn't the "snap to point" or "snap to curve" seem to work when I move edit points of curves on surfaces?
COS have limited snapping capability and IMO not a recommended to mess with as a new user. best bet is to extend or use Curve Section to cut them.

7. How can I delete a curve on a surface? (When I use "select object" on it, which works on normal curves, the surface also gets selected, and thus deleted if I use the "delete active" command.)
someone else answered this.

Drag Keypoint tool along with all the other Keypoint tools were combined in a single tool box a few years ago. many users use them only for specific task and not through out the entire modeling process. doing this really reduced the number of options in the curve creation menu.

PICK NOTHING. haha. love to hate this one as well. it is a very odd concept. its a combo of "complete", "deselect" but does not leave the tool. unfortunately most of us have learned bad habits around this one. to reduce the use of it... try holding SHIFT to take you back to the selection mode of any of the transforms. you can also get rid of it all together, by using only PICK OBJECT... you can Deselect(replace) by click with the middle mouse button in an empty space.


Degree Vs Spans. in short. Single span geometry is called Bezier and the math is simpler and smoother. this is most important if you want to sculpt the CVs.

Re: The thread for silly Alias questions...

Postby eobet » November 9th, 2009, 4:02 pm


eobet
step three
step three
 
Posts: 189
Joined: February 4th, 2007, 7:14 am
Location: Limbo
Thank you for all your answers!

I will digest them and then post more silly questions the next time I fire up Alias! :)

Re: The thread for silly Alias questions...

Postby Cyberdemon » November 9th, 2009, 4:45 pm

User avatar

Cyberdemon
full self-realization
full self-realization
 
Posts: 3282
Joined: February 7th, 2006, 11:51 pm
Location: New York
I think the toughest part about Alias (and almost any professional software for that matter) is that there are a LOT of different ways to accomplish the same thing. So even with a crappy UI, there are still best practices that are fundamental to the creation of 3D geometry that can't be expressed simply.

Those things you learn over the course of learning a program, but I can't tell you how many times I figured out to do something and used that technique until I found out later there was a way that was 50% easier to do it.

Once you learn those best practices though, the tool can become a beast.

Re: The thread for silly Alias questions...

Postby eobet » November 14th, 2009, 8:23 pm


eobet
step three
step three
 
Posts: 189
Joined: February 4th, 2007, 7:14 am
Location: Limbo
Cyberdemon wrote:I think the toughest part about Alias (and almost any professional software for that matter) is that there are a LOT of different ways to accomplish the same thing. So even with a crappy UI, there are still best practices that are fundamental to the creation of 3D geometry that can't be expressed simply.


Not sure what your point is, but in Solidworks (the app I'm used to), there are also a huge amount of ways you can build the same thing, but unlike Alias, it has an excellent UI, and gets better and slicker with every release (I'm still on 2009, but that was a huge improvement over 2008, with the context sensitive quick tool popups that displayed the most common and relevant actions you might want to perform on the thing you just clicked on).

In alias, however, I even find the radial menus cumbersome (which people hail as proof that Alias does indeed update its UI), and I've opted to map single stroke hotkeys for my most common used actions instead (C for CV, N for nothing and M for move, for example).

Which brings me to my next question:

Spacebar, the largest key on the keyboard... is it used by anything in Alias by default?

Not sure how to map it to anything either (I'd like to map it to "pan" so I don't have to press two bloody modification buttons in order to just scroll a viewport).

Re: The thread for silly Alias questions...

Postby Brett_nyc » November 15th, 2009, 3:16 pm


Brett_nyc
full self-realization
full self-realization
 
Posts: 875
Joined: May 30th, 2006, 9:57 am
Space bar acts like "Enter". I just whack it to accept any and all commands that require a confirmation. It gets a lot of use during sessions with a lot of trimming, trim divide, etc where it maintains you're most recent option, but still requires a confirm.

Re: The thread for silly Alias questions...

Postby Evangelist » November 16th, 2009, 10:05 am


Evangelist
step two
step two
 
Posts: 83
Joined: April 3rd, 2009, 3:44 pm
the Space bar brings up the Painting HOTBOX when working in the Paint Layout window and a Pencil is selected.
alias_design_sketch_interface.jpg
alias_design_sketch_interface.jpg (60.47 KiB) Viewed 11361 times

Re: The thread for silly Alias questions...

Postby eobet » March 1st, 2010, 4:51 am


eobet
step three
step three
 
Posts: 189
Joined: February 4th, 2007, 7:14 am
Location: Limbo
Ok, so I've properly begun my Alias training now, and I see that some of the questions I asked doesn't make sense. Kudos to those who managed to answer them anyway! :)

Next question is still (unfortunately) a keypoint curve question:

How can I "lock" the center of the radius of an arc to a certain position? (I know I can move the pivot at then reposition the arc at my specified fixed point, but I would like to be able to edit the arc in place without having the center of the radius ever move.)

But I also have one for the surface geeks out there:

Image

How can I increase the accuracy of trimmed surfaces? I have tried to rebuild the originating surfaces and curves in a few ways, but nothing seems to matter in this particular instance. It's also weird that the surface evaluation tool complains about angle deviations in tangency alignment, but the surfaces are only aligned with position.

PS. Wow, Evangelist, did you model that head in Alias, or are you just painting it in Alias? Either way seem rather masochistic, though. ;)

User avatar

Cyberdemon
full self-realization
full self-realization
 
Posts: 3282
Joined: February 7th, 2006, 11:51 pm
Location: New York
Eobet,

Not 100% positive on what you're trying to ask for the arc question - when you say you want to "edit" the arc without the center, what kind of edit?

Regarding the trimming issue - my bet is you're just running with the default tolerances which are too loose. I attached a screen shot of my tolerances. Try updating them in the contruction settings, specifically the fitting options.

Let me know if that helps.

tolerances.jpg
tolerances.jpg (55.53 KiB) Viewed 11130 times


Evangelist
step two
step two
 
Posts: 83
Joined: April 3rd, 2009, 3:44 pm
im pretty sure ( i dont use keypoints for construction) the behaivor of the Circle is what you are looking for. its the only keypoint "arc" that the radius is based on the center NOT the sweep inputs.

Surface Geek stuff.
im very doubtful that your surface is moving. trimming does not rebuild or reinterpret the shape. what you are possibly seeing is the Draw Precision of the surface change after the trim. try this. CONTROL PANEL > QUALITY > DRAW PRECISION set this to 1 and see if the shape looks better. my fingers are crossed for ya. if so, everything displayed in a computer is a polygon or polyline. after you trim, the flag segment might be showing right where you trimmed. setting this to 1 is the maximum number of segments to draw a shape. set it to zero you will see the segments very clearly. BTW: this is not set to 1 by default because it will slow the display down especially for super dense models.

i could get into tolerances if you need but i would first start with the display.


Masochistic. Thanks: ) but i did not model this head. it is one of the human models that came on the 3DCD (if anyone remembers that) once upon a day, Alias was called Power Animator and was a real hit in Hollywood hence all the animation tools still in the software. if you want to see some of the first uses of Alias, check out Abyss(the water creature) and im pretty sure Terminator 2 (the chrome guy).

Re: The thread for silly Alias questions...

Postby eobet » March 1st, 2010, 10:32 am


eobet
step three
step three
 
Posts: 189
Joined: February 4th, 2007, 7:14 am
Location: Limbo
Thank you for the tips!

Turns out, it's not the trim that's inaccurate, but actually the projection, and it didn't matter that I used your construction options:

Image

Granted, that's an enourmous zoom, but still... I was able to spot it at normal zoom without even using evaluation.

Absolutely no idea how to make it go away.

Regarding the arc... when you create a three point arc, you get a fourth as well... that fourth point is the center of the radius, and that's the one I want to lock down, so when I drag the three other keypoints, the "origin" stays put.

Re: The thread for silly Alias questions...

Postby eobet » March 1st, 2010, 10:37 am


eobet
step three
step three
 
Posts: 189
Joined: February 4th, 2007, 7:14 am
Location: Limbo
Whoop... an answer while I was posting the second one...

Evangelist wrote:Surface Geek stuff.
im very doubtful that your surface is moving. trimming does not rebuild or reinterpret the shape. what you are possibly seeing is the Draw Precision of the surface change after the trim. try this. CONTROL PANEL > QUALITY > DRAW PRECISION set this to 1 and see if the shape looks better. my fingers are crossed for ya. if so, everything displayed in a computer is a polygon or polyline. after you trim, the flag segment might be showing right where you trimmed. setting this to 1 is the maximum number of segments to draw a shape. set it to zero you will see the segments very clearly. BTW: this is not set to 1 by default because it will slow the display down especially for super dense models.


Thanks for the tip! Unfortunately, on the OS X version of Alias Automotive 2010, that option doesn't seem to be availible. There's only a "tolerance" setting and a tessellator toggle, and those does not seem to have any effect at all.

Hopefully you are right, and it's only a screen artifact. We'll see when I'm starting to fillet (though I've heard that fillets can actually fill in gaps in Alias, which sounds nice).

EDIT: Never mind! It worked! Thank you!

But I will leave my original answer above just as a testament to the absolutely HORRID user interface in Alias. The problem is the small black arrows which points down in front of the "Quality". First of all, since there is no outline around the collapsed menu, I sometimes have trouble reading it as a menu at all. Second, a down arrow in my mind means that the menu is opened. I know, I know, it's an ambiguous solution. Hmm... could that be why some applications use a RIGHT arrow instead?

My teacher showed us Alias 2011 and I just had to laugh. The only UI "update" I saw were that the buttons were slightly shaded... looked about as good as Windows 95 did... in 1995. It's not even a step up from the Windows 3.x styling they use now. Autodesk really needs to fire all of their UI designers... but then again, I suspect they have none, and what they really need is to hire some (hey, I'm available in 1.5 years time if they want to). :)

EDIT 2: I don't know if I should laugh or cry this time... when you click the "down" arrow to open the collapsed shading menu... there is an actual bloody right arrow at the very bottom... which not only is in a completely different style than the other arrows, it doesn't have any accompanying menu label as with the rest... only a single black line which goes right through the arrow... ok, I'm crying now.
Last edited by eobet on March 1st, 2010, 10:59 am, edited 2 times in total.

Go to the Next Page

Return to software and technology