EIM Tips [Archive] - dvGarage Forums

Paul S.

04-19-2002, 09:17 AM

Hi,

I've probably mentioned this a number of times before but thought it worth mentioning again as it tends to come up fairly regularily.

EIM is a nurbs modeler....... successful use requires some work (experimenting) and understanding of the tools to use. Many are familiar with bezier curves and while they may feel more comfortable they aren't the curve type to use most often with EIM. They are great for logos and text but for smooth organic surfaces tend to introduce too many faces which can lead to problems as you refine your model.

One very powerful aspect of EIM is it's solid tools which are untouchable for kniving, booleans and fillet/bevels. Introducing unneeded complexity (by using bezier curves which increase face count) causes more errors, when complex rounding is attempted, than really needed.

So just as a first post in this forum I thought I would re-mention this. Anything which needs a sharp corner and a simple extrusion is fine with a bezier curve but for general moodeling in EIM get familiar with nurbs curves and use them.......and use only as many knots as really required to define the needed shape.

Simple (fewest knots, surfaces, etc) geometry is really the key to having good success with EIM.....as with any nurbs modeler.

A Lindsay

04-19-2002, 02:24 PM

Thanks Paul!

I'm really excited to have you as the Moderator for the modeling section.

Alex, aka lowly monk in presence of master.

Paul S.

04-19-2002, 02:44 PM

Originally posted by A Lindsay
Thanks Paul!

I'm really excited to have you as the Moderator for the modeling section.

Thanks Alex....great to be here!

Alex, aka lowly monk in presence of master.

lol....it may be the other way around I think:-)

Tom Vincze

04-20-2002, 11:07 AM

Paul-
Welcome and thanks for the tips. Being hardwired in Illustrator (design background), Bezier seems the easy way out. When you mention NURBs, is there a particular use better suited for them? Character modelling for example? If I were bulding a model with a lot of hard edges, like a building, are the solid primitives still safe in this regard?

Tom Vincze

04-20-2002, 11:20 AM

BTW, your work is great! Nice inspiration for us. I notice in general, in magazines and sites for example, that programs like Lightwave, Maya and Max 3d are often mentioned, but EI is so rarely mentioned, yet in my opinion, it can produce such nice looking renders. Why is that? Did EI lose out in the feature wars, or are those oft-mentioned apps better a certain things than EI? Just curious.

Paul S.

04-20-2002, 11:43 AM

Originally posted by Tom Art
Paul-
Welcome and thanks for the tips. Being hardwired in Illustrator (design background), Bezier seems the easy way out. When you mention NURBs, is there a particular use better suited for them? Character modelling for example? If I were bulding a model with a lot of hard edges, like a building, are the solid primitives still safe in this regard?

Hi...and thanks:-)

Bezier curves are pretty much the only way if doing graphic design....especially with eps imports via Xspline or with EIMv4.0

Editing eps in eim it is essential to know beziers and understand how to deal with them so eim likes them.

Nurbs curves are the only ones to use if an object will become 3 dimensional other than a simple extrusion.

When creating any design work within eim I always use the knife/boolean toolset along with filled double-sided curve primitives and nurbs curves.

This is an old example I dug up which shows a very workable approach to using this technique. I uses the best on eim in combo ensuring sound geometry.

Basically using filled rectangles, circles etc and booleaning them together or subtracting them...also nurbs curves to knife sections out from the double-sided planes.

Once the shape is defined I go to the face toolset and use the "uncover face" tool....leaving the curve which can now be extruded but using only the amount of knots which are essential to define the shape and not any more.

http://poison.anapraxis.com/dev/anadexer/repository/public/psherstobitoff/Tests/Wires.jpg

Paul S.

04-20-2002, 11:55 AM

Originally posted by Tom Art
BTW, your work is great! Nice inspiration for us. I notice in general, in magazines and sites for example, that programs like Lightwave, Maya and Max 3d are often mentioned, but EI is so rarely mentioned, yet in my opinion, it can produce such nice looking renders. Why is that? Did EI lose out in the feature wars, or are those oft-mentioned apps better a certain things than EI? Just curious.

Thanks.

In certain ways EI is a little behind in features and in others well ahead of the pack. As an example I recieved a call on thurs to produce an illustration about 7000x3500 pixels fully raytraced and will probably need to have 2-3 million polys to maintain geometric integrity at that resolution. There is no other program which would even come close to allowing me to meet my deadline....if it could render it at all.

The Play years were hard on EI in some cases and it fell behind in some of the "feature parade" needed for marketting purposes. Only recently has it become very good for character work....and lastly the advertising budgets large companies have tend to over-shadow smaller operations like EI. But even still EI is used in many movies for what it does well.

This is all just personal opinion though.

Paul S.

04-20-2002, 12:06 PM

Tom Vincze

04-20-2002, 12:10 PM

The image really helps. I'm wondering, since you only show the cross section, and then the solid, at some point, did you create ribs to skin it? The reason I ask is the solid curves in toward the center on the front and back sides. What's the missing step? How did you do that?

Regarding EI, I think renderings posted on sites market better than anything else. I'm sure it wouldn't hurt if more people posted, or sent EI work to magazines, etc. I will if Iget to that point. In my case, before I got the Toolkit, I looked at EI's gallery and saw some impressive work. That helped make the sale. Maybe here at dvGarage, there could be a gallery as well. I think it would certainly help sales.

Paul S.

04-20-2002, 12:34 PM

Originally posted by Tom Art
The image really helps. I'm wondering, since you only show the cross section, and then the solid, at some point, did you create ribs to skin it? The reason I ask is the solid curves in toward the center on the front and back sides. What's the missing step? How did you do that?

Regarding EI, I think renderings posted on sites market better than anything else. I'm sure it wouldn't hurt if more people posted, or sent EI work to magazines, etc. I will if Iget to that point. In my case, before I got the Toolkit, I looked at EI's gallery and saw some impressive work. That helped make the sale. Maybe here at dvGarage, there could be a gallery as well. I think it would certainly help sales.

In this case I duped, Command+D the original.....moved and scaled it down and then once again creating 3 profiles to skin. Skinned with caps on creating the solid.

mannyp

04-20-2002, 06:44 PM

Hey Paul,

Can you post a general breakdown of the procedure? I tried to replicate what you did to no avail. :\

TIA!

Paul S.

04-20-2002, 09:00 PM

Basically one is using booleans and knives to carve out a shape...imagine using cut-out pieces of paper stacking them on top of each other. Some are rectangular and come circles, oval etc.

Once the shape is the way you want it....laid out flat all on the same plane, boolean these shapes together all at once.

These shapes need to be made from double sided surfaces....activate double-sided in the curve profile dialog before creating them.

Once you have a single object because of the boolean procedure then go to the face pallet and use the uncover tool. All that should be left is your outline (wire). Now this outline can be copied, moved and scaled as I did to create the solid in the image after using the skin tool....so basically you have a number of profiles all the same but moved apart, scaled and rotated which are then used with the skin tool.

Also it is possible to use nurbs curves as knives to define your sheets before the boolean...you can also subtract shapes using the boolean subtract.

This is a very visual way to create profiles and all tools which relate can be used in the procedure.

I hope this makes sense....if you still have trouble tell me what you are doing and what is the "unwanted result".

Curt

04-22-2002, 11:30 AM

Man, I can tell already I'm gonna be hangin' out here a lot!
Cool, you can edit your posts as well (nice job Alex). Anyway, I do have "An area of weakness" that I wonder if you could shed a little light on. I've tried a number of times to produce surface blends and rarely come away happy. Do you have any "Essential DO's & DONT's" regarding blends and NURBS surface editing that might steer me away from eminent danger or guaranteed failure because I seem to be able to reproduce those sorts of results almost effortlessly.

Paul S.

04-22-2002, 03:49 PM

Yeah, I see you edited your post, as I had read it earlier and the request for info in surface blends wasn't included at that time.

Well, let's see. The surface blend tool, "blend from edges" has it's limitations and unless one is using eim v4.x I probably wouldn't recommend it much. It creates a very,very dense ACIS structure which will slow down everything to somewhere near a crawl. Not always but mostly.

Now in v4.x, which I think you have, it is essential to use the "reduce knots tool" in the nurbs edit toolset to ....well, reduce the knots and if holding down the shift key at the same time it will maintain the boundary and chances are will stitch back to the main body...not always. Boolean join will have to be used then.

That's not really more than a clean-up operation anyways, but essential, I've found in many cases.

These are the cases where I will venture into using the S2S (surface to surface which I will call the blend from edges tool from now on).

Do not really attempt multiple edges and expect results. For example a hole cut out using a bezier curve will have multiple edge...stay away from the s2s tool.

Only use a very simple nurbs curve to cut an opening to blend and don't have any tight corners what-so-ever.

Only simple geometry will be somewhat predictable so anything really complex should possibly be attempted but don't have hopes too high.

I alway just leave all check-boxes active except for "perpendicular"

Most times I leave things at 1.0 for each field but times have to go to .5 or 3-4 to get the look I want.

If you get the u and v in same or opposite directions error turn the "perpendicular" field to active.

That's kind of all I can think of for now...keep it way simple and don't ask a whole lot from it...it can surprise with great results but at times just kinks the hell out of the generated surface...and it is slow.

Mirroring a surface and doing a blend between them resulted in needing a negative number input for the mirrored object to get a result...not sure if this bug has been fixed or not....not a big deal if not.

Hope that helps a little and if you have specific questions please ask those.

Curt

04-22-2002, 04:26 PM

Paul,.
Actually it helps quite a bit. It certainly explains some of the errors I've been getting. Interestingly enough your comments on rounding/NURBS curves turn out to be just as useful for explaining some of my blend errors as well. Sometimes I'd have what I would consider to be relatively simple wires but they'd give me all kinds of grief and yet other times I'd be using decidedly more complex curves (almost all of this in experimentation) and think "there's no way this will work", and it does. Obviously HOW the the wires are created plays a big part in the success of the function. I'd long be a bezier fan having spent a lot of time in Freehand & Illustrator so I was always reaching for the bezier wire tool and then converting with the bezier to single spline tool (whoops!). Well live and learn. Thanks for the great info. I feel confident now I can forge ahead into a whole new realm of problems that previous to now I wasn't even able to get at.

Curt

Paul S.

04-22-2002, 04:46 PM

Glad it helped some:-)

This is a link to a bunch of additional tips....some very good:

http://www1.linkclub.or.jp/~inosuke/html/e_index.html

The one where he explains using "hulls on nurbs" will help out on transitioning from beziers to nurbs curves.

spike1201

04-27-2002, 02:08 PM

Okay Paul, I've tried to duplicate your Thingamabob in Modeler and got close. Really close. But the top left part of your shape is getting a little twisted when I skin it. Any ideas on how I can fix this?

I duplicated the shape three times, spread them out in order, and then scaled the middle one down a bit. Then selected them in order with the Skin tool. The rectangles on the left get twisted about 90 degrees as it's skinned. I'm so close, but not quite there. Thanks for these tips!

Spike

Kim

04-27-2002, 02:34 PM

Great thread!

I have understood that NURBs were the way to go for 3D construction (as opposed to beziers), but I have a question about NURBs.

Since beziers are inherently better for creating sharp corners, this raises the question of how then to best use NURBs for sharp corners. I know that one can weight the NURBs anchor points to create sharper corners, but I have read that this causes problems and that one should avoid weighting.

Should we avoid weighting altogether? Above certain levels? When planning on doing certain operations afterward?

Kim Hill

urban ape

04-27-2002, 03:45 PM

Spike

It looks to me like you have the direction of your wires misaligned. Try checking the Auto align direction box in the skinning settings. If that doesn't work try going back to your original wire and recopying it.
When you skin objects you sometimes get some very strange effects because everything gets misaligned.

spike1201

04-27-2002, 09:55 PM

Thanks for the advice, but "Auto Align Direction" did not solve the problem. Nor does duplicating the wire all over again. I also tried reversing the wire direction on a few of them and all gave me identical results.

Any other thoughts?

urban ape

04-28-2002, 02:47 AM

Spike

I though I would go and look at what Paul did but I cannot get the link to open (I will try again later) so that I could see the process you used. I think I have spent far too much time working with software that is sensitive to this problem. Sometimes the problem is created when you make the original shapes. You should always try to draw them in the same direction because this operation is sensitive to origin points and the like. It may pay you to review your original process and see if you created the 2 squares in the same way, you may have made them in oposite directions.

One more suggestion is go into the system preferences and check show edge directions, this will enable you to see if there is a probem. Then go into the wire editing palette and choose reverse direction. This might possibly solve your problem it usually works for me let me know how it goes. I will get back to you when I have got Pauls link open.;)

Paul S.

04-28-2002, 05:52 AM

Originally posted by Kim
Great thread!

I have understood that NURBs were the way to go for 3D construction (as opposed to beziers), but I have a question about NURBs.

Since beziers are inherently better for creating sharp corners, this raises the question of how then to best use NURBs for sharp corners. I know that one can weight the NURBs anchor points to create sharper corners, but I have read that this causes problems and that one should avoid weighting.

Should we avoid weighting altogether? Above certain levels? When planning on doing certain operations afterward?

Kim Hill

I ususally never use weights for nurbs curves thought not saying don't. They create a rational curve (rational=weighted) and any surface created from them becomes rational also......in EIM V4.0 you have some very nice nurbs surface editting tool but you have to convery rational surfaces to non-rational to use them to their full potential so I don't bother with weights....just add a few more knots to geta similar look.

Don't try to use weights to create a sharp corner.....that will lead to disaster;-)

Two way to do it which work fine.

Creat all of the sharp corners with pieces of bezier cirves or poly lines and the curvy part with nurbs (snap at vertex to ensure alignment).....make sure the wires are all traveling in the same direction and boolean them together.

Use double-sided surfaces (rectangles for example) to create the shape needed and boolean them together to form on sheet...then use a nurbs curve for a wire knife to add in the curves parts. Uncover with the uncover tool in face pallet.

Just because beziers aren't the favorite for creating surfaces doesn't mean you can't use them...any of these rules or "shoulds" can definitely be broken.

Paul S.

04-28-2002, 05:56 AM

Originally posted by spike1201
Thanks for the advice, but "Auto Align Direction" did not solve the problem. Nor does duplicating the wire all over again. I also tried reversing the wire direction on a few of them and all gave me identical results.

Any other thoughts?

It shouldn't be twisting as you are using the same profile just duplicated. all points should already be aligned. Did you do any non-uniform scaling. If so this might add some extra points?

Step it back to just 3 duplicate profiles not scaled and not rotated....does it still twist? It really shouldn't.

If that works fine then scale the middle one some and see the results, etc. Somewhere along the way you should be able to tell what went wrong.

spike1201

04-28-2002, 05:35 PM

Yep, if I skin with three identical shapes, I do not get the twist. When I scale the middle one, it twists when skinning. I guess I'm scaling it wrong (uniform scale tool). What's the best way?

Kim

04-28-2002, 06:30 PM

Originally posted by Paul S.

...
Just because beziers aren't the favorite for creating surfaces doesn't mean you can't use them...any of these rules or "shoulds" can definitely be broken.

Thanks for the great tips, Paul!

Paul S.

04-28-2002, 08:04 PM

Originally posted by spike1201
Yep, if I skin with three identical shapes, I do not get the twist. When I scale the middle one, it twists when skinning. I guess I'm scaling it wrong (uniform scale tool). What's the best way?

I just went and tried this and there seems to be a point in scaling where it breaks the skin. I'll have to report it as a bug or get some common-sense info on why this would occur.

I found that scaling is fine up to a point and then for some strange reason, if scaled just a little further, the skin twists. Shouldn't be doing it as all profiles are aligned and contain the same amount of points.

ErickG

04-29-2002, 12:32 AM

Hey Paul,

Erick Geisler here! Great to see you are a moderator on this forum!

One question I have for you. Is there any way to use subdivided surface modes with EI. I know you can import the mesh and subdevide but is there a way to use the low poly cage for animation and then subdevide at render time?

-Erick

P.S. I will send you some tests I am doing with the entropy rendering system. There are some AMAZING! stuff you can do with Entropy. I rendered an image at 4K with true DOF and sub-pixel displacment with over 10,000,000 polys on a machine with less than 512K Ram.

Paul S.

04-29-2002, 06:11 AM

Originally posted by ErickG
Hey Paul,

Erick Geisler here! Great to see you are a moderator on this forum!

One question I have for you. Is there any way to use subdivided surface modes with EI. I know you can import the mesh and subdevide but is there a way to use the low poly cage for animation and then subdevide at render time?

-Erick

P.S. I will send you some tests I am doing with the entropy rendering system. There are some AMAZING! stuff you can do with Entropy. I rendered an image at 4K with true DOF and sub-pixel displacment with over 10,000,000 polys on a machine with less than 512K Ram.

Hey Erick.....thanks and good to see you stop by.
I've been asking for SDS at render time but not implemented in EI yet. There is/was a pluggin called "stunt double" which allowed one to swap low-res/hi-res but not sure if it is still available.

Sounds like quite a renderer....definitely send the stuff to me.

spike1201

04-29-2002, 08:00 AM

Hi Paul,
It's me again. Are you sick of this long thread yet??
Okay, I'm at work and I've rebuilt that Thingamabob in Universe Modeler 4 and everything worked on the first try. Woo-hoo! No twists!

Now, at the risk of getting this thread off-topic, I'd like to round this object but I'm getting errors (error types vary when I vary the radius. What do I need to do to succussfully round this bugger?

Again, thanks so much for devoting so much of your time to us newbies. I've learned A LOT from this "exercise"!

Paul S.

04-29-2002, 08:20 AM

Glad it's helped.

First of all it isn't recommended to try to round the whole onject at once. Guaranteed to have criptic errors if you try.....very simple objects can work but most times it's too much to ask of EIM and if something is failing it's almost impossible to see where.

Right off I'm sure your radius is too big. On the left-habd side where the squigly shape meets the circular one the squigly shape is too thin for the rounding ball to travel down both sides without colliding into itself.

What I suggest you do iis 1) turn preview mode to simple wireframe. This will show you all your edges very cleanly. Or leave this view in shaded mode but do all of your edge selection in a different window (set a simple wireframe) with the view rotated. As a note, it's actually very useful to have more than one view in iso view. Seldom do I work with all standard views. Option+V+click in view, toggles from simple wireframe to shaded.

2) Just round the edges traveling along Z first. Pick at "edge" and select those one at a time...once all selected commit the round.

3) Set pick to face and then round the top and back face. It's usually best to set a smaller face round radius than the Z edge round radius. Even .01 smaller can allow for rounding of the face when the same radius as the edges fails. Not always the case but enough times where I just do it out of habit.

This should work fine if your radius is not to large for the object. It would be great to be able to enter any radius you wanted and have EIM recalculate all of the surfaces even where the radius collides with itself...and in some cases eim will...but mostly not.

spike1201

04-29-2002, 10:28 AM

Woo-Hoo! I've finally figured it allllllllll out!

Rounding an object in this way was not my first instinct, but your description was well written and I had no problems. Actually, that's not true. I did #1 and #2 easily, but got into trouble when I tried selecting the front and back faces (#3). I couldn't get what I wanted selected. I finally used the edge filter and then marqueed around everything, held shift and then marqueed around everything again except for the two faces (using the top view). That finally did it.

Paul, and everyone else who's contributed, thank you so much for taking the time to help me attack this. I learned as much through this "exercise" as any tutorial from dvGarage! I can see that a lot of people have read through this thread. If you're just reading and not doing, go back and actually try it. It's worth it to get your mouse dirty on this one. It's really opened my eyes on how to get the shapes you want into Universe.

A Lindsay

04-29-2002, 10:38 AM

Great work!

a

Paul S.

04-29-2002, 11:12 AM

Good for you!....glad to see you get done and persist till you got what you wanted....looks great!:-)

Getting mouse dirty is the only way to learn to use EIM.

Paul S.

04-29-2002, 11:43 AM

On selecting the face to round ......make sure you have your Isoparms visable (I+click in view toggles on and off) and select that with the pick or rounding tool. This will ensure you do not miss any tiny edges which can become invisable to the eye if a dense object is worked on.

While in the rounding tool it is possible to use different pick settings...for example select the main face with "face", then if a few edges aren't to be rounded select "edge" and with "shift" +click unselect these edges. Useful to go back and forth while slecting what needs to be rounded.