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Gorf

Smoothing technique?

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Is there an established technique for smoothing the surface of a model without each tweak of a CP affecting all the others that are linked through splines?

 

I've made a helmet which could do with being perfectly smooth, but has ridges as a result of modelling the nosepiece and eye-holes.

post-1449-1218416201_thumb.jpg

post-1449-1218416295_thumb.jpg

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Can you select all the cps and press the F key to flip the patches. In that image the patches are transparent which makes it hard to make out what's going on. From what I could see, you have a few dead ending splines which is where the creases are. No bias tweaking should be necessary to get rid of creases.....it's all in how the splines flow.

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You don't need double splines running around the eyes and going down around the helmet. Remove one of the two and you will have a much easier time smoothing out the rest.

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Thanks for the replies, everyone

 

You can tweak the bias of the point without moving it so it is smooth.

I always try to avoid bias tweaking. On the rare occasions I've tried it, it's been hard to keep them in situ. As soon as I move any CPs the bias resets...

 

...In that image the patches are transparent which makes it hard to make out what's going on...

That's just me trying to be clever (and, evidently, failing). I've just superimposed a wireframe and used photoshop to erase the background so the render shows through. I should just have used shaded wireframe mode.

 

You don't need double splines running around the eyes and going down around the helmet....

Thanks - I'll try that today at work ;) and report back tonight.

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There is of course the porcelain-material, but you will have to get rig of the creases anyway.

 

*Fuchur*

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A big help for me is using the constraint keyboard shortcuts to keep from moving CPs in directions that I don't want them to go. Like, for instance, holding down the "1" and "3" keys mean I can move it side to side and front to back, but not up and down.

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I'm always impressed by people like Will Sutton who can make a smooth face and not seem to need to tweak any biases to do it.

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I move points very carefully while in shaded mode. I rotate the view at a steep angle to the surface to see the "bumpy" spots, I then nudge the points that are causing bumps until it gets smooth. It can be tedious but it works. It really is all about the flow of the splines. If the patches are evenly spaced and the splines flow smoothly the smoother the surface. Whenever there is a turn or a point that causes an abrupt change in th direction of the spline you could get a bump.

 

For something like a helmet or a "mechanical" or man made object that has an "unnaturally" smooth surface think about that during creation or modeling too. If you start with a "smooth" spline and extrude/rotate/extrude/rotate the surface is more likely to stay smooth. It maintains that continuous surface and equally spaced patches. Hard to explain. It is the same as when you create a sphere by using the lathe. You never get bumps because everything is smoothly and perfectly oriented. You goal in smoothing a surface is to get that kind of perfect patch layout.

 

Don't forget... sometimes perfectly smooth is a bad thing. I would expect a helmet like this to have dings and bumps even when new.... just an opinion. I love mechanical modeling and try to add those kind of imperfections on purpose.

 

-vern

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I have been using the same as Vern mentioned and combine that with short key "4", "5" or "6", but the most important is that you have to get splines flown continuously in the first place. I then use bias to adjust the contour of a spline between two CPs which can only be adjusted by using the bias, because by adjusting one CP will effect those that connected to the one you adjust. These are what I have learned so far from my last two WIPs.

 

CHEERS!

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Thanks for all the advice, folks. I'll get chance to play with it later today. Vern, I agree that a bit of "weathering" would make it look better, but in this case it needs to be perfectly smooth.

 

I can see how lathing the helmet would result in perfection, but then I'd need to use cookie cutters to get the nosepiece, right? Is that considered "cheating"?

 

My A:M PC is now connected to the internet, so I can more easily post images of the work...

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I can see how lathing the helmet would result in perfection, but then I'd need to use cookie cutters to get the nosepiece, right? Is that considered "cheating"?

 

There is no cheating and if booleans or cookie cutters work go for it.

 

However I was thinking more along the lines of extruding. Imagine you created a perfectly smooth curved spline that defined the top edge of the helmet , above the eyes and nose. By extruding and scaling/rotating that spline from a specific origin point you can define those large areas that need to be smooth. If you plan carefully ahead of time this extruded spline can even have enough points included to account for creating the eye and nose pieces or you can use the "shift" key to add points without disturbing the curve of the spline.

 

I love that shift key when adding points. EDIT: Check out the tutorial "Adding Control Points" (the fourth one) Done right you can stitch in things very nicely without disturbing a smooth shape. The irregular splines of the eyes and nose could be stitched in this way and those splines carefully stitched up the surface to hooks. The key is maintaining the spline "flow". If you dead-end a spline hook "too soon" it causes a bump or crease. Try hooking it further back. If the cross section of splines is smooth, carefully stitching in splines using the shift key when adding points will not disturb the smoothness. This model is in a category I call "mechanical" or "fixed" or "non-organic". It doesn't move. This is a bonus because you can do what ever is needed to maintain the smoothness without worrying later if point motion will cause bumps or creases. There is no point motion (unless you put in dents with an action).

 

That's another key thing... low patch count (you have that already but it's worth mentioning) the lower the spline count the easier to keep things smooth.

 

Another trick is to NOT move individual points as much as possible. Only rotate or scale using a whole spline cross section or the whole model and the distortion box grid thingy. You could even distort a high patch sphere into the basic shape of the helmet using this technique, then punch in eye and nose shapes. Let's say a cross section spline needs to move up higher for some reason, or a set of points needs to move up, don't try to move each point, find some way to rotate that whole spline so the splines maintain smoothness, or even stitch in a new set of splines (with the shift key of course).

 

I am not an expert in this kind of mechanical modeling by a long shot, so many others can do it so easily it seems, car models, beautiful curved surfaces. It's hard to explain... when you need a smooth curved surface the trick is to either model it that way using extrusions to maintain the flow of splines or global distortions to get the shape you want. Distortions that modify the whole shape so you are less likely to get bumps. If you need to add spline density to an already smooth surface make sure you use the "shift" key with the add point key.

 

If your patch count is low it can be easier to nudge points to smooth things out. I've done that before. As I said it can be a bit tricky and tedious but you can smooth a curved surface with careful nudging.

 

I wish I could explain it better. Maybe this is a subconscious thing from using AM for so long. One more thing, and this is just my humble opinion... perfection has flaws. Even what you think should be absolutely smooth... in real life there are flaws, slight imperfections to catch the light and break up the surface. A perfectly smooth or flat surface just... doesn't look real to me. If you use any kind of materials or decals to break up the surface or give it some kind of texture this can also hide "flaws" in the surface. Don't forget as well... how long is the object on screen? If it is in motion or part of an action sequence the flaws might never be seen at all. Just a thought.

 

EDIT:

 

Adding thickness to the edges. Your helmet appears to have thickness. Thickness can be simple, just extrude an extra set of splines on the edges of the open surface and "fold" them back inside creating an illusion of thickness with out all the fuss. I used that technique on some parts of my terminator model. There is really no need to model an entire interior surface if it is not needed. Maybe in the case of the helmet it might be necessary. the trick then would be to just copy the whole helmet and scale/distort it to fit inside and connect it at the edges.

 

-vern

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Wow, Vern - many thanks for such a comprehensive answer. So far, your explanations have made perfect sense, so either you're clearer than you think, or I'm as weird as you. ;)

 

Well, I've nailed it with the help of all you folks: The extra spline needed to go, and Vern's advice about using an oblique view and when moving CPs (plus doing them in one plane only) did the trick.

 

The way I actually modelled the helmet was to start with the nose guard and eye holes in the front view, plus the outline of the head. Then, I made a single spline for the head shape in the side view, and joined everything up. That's why the horizontal splines sweep up from front to rear - it wasn't lathed, which was my first instinct for modelling it. The "shift key" tip is a useful one. I think I'll be using that one soon. It's OK for now, but there are far too many five point patches for it to be "good" modelling. I'm only getting away with it because it's a rigid object - it won't animate, as Vern says. There is also one last bulge that I didn't bother removing- everything else looks OK, so as this one will eventually be hidden by a crest on the helmet, it wasn't worth fixing it.

 

As for thickness, I've done it exactly the way Vern said. There's a little bevelled edge courtesy of one of Yves' tutorials (I think it was Yves) then the surface goes into the helmet and then up. It might not be far enough for close inspection, but I'll deal with it later if need be.

 

If I finish it in time, this will be an entry in the SciFi/ Fantasy comp. That's why I've not posted a pic just yet. The finished image will be very different to what you're expecting. I'm being deliberately vague to avoid prejudicing any results... Don't want to attract the sympathy vote, you see... :P

 

Thanks again everyone. Now I need to go ask that weird wasabi woman a Photoshop question... I wonder if she reads the newbie section...

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Don't worry about 5 point patches on a "non animating" model. If a 5 point patch looks okay... then you're golden. It is NOT bad modeling to use 5 pointers as long as you are happy with it and it looks good in a render. That's what they are for. I use them a lot in mechanical modeling because they help cut down on spline count and they are great for... relatively "flat" areas. A slightly curved surface can often be okay with a 5 point patch. It is when the patch is severely twisted or "bent" that you might have problems. As long as the points in a 5 point patch are relatively evenly spaced apart they work great. If one of the points is "in line" with another point you could get creasing or artifacts. the trick with 5 pointers is that they are as close to an equal distance from each other as possible... not an expert... just my observation.

 

If you look at some primitive models 5 point patches are used extensively. They are also used when attaching limbs. I have models where a cylindrical shape attaches to another shape and the joint area is ALL 5 point patches. 4 around the join. This might not be the best scenario due to bending, the key is to get those 5 pointers in the right spot so they don't cause trouble.

 

-vern

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Just a heads up, be very nice to Nancy - Wasabi woman. She is very skilled and very creative, not wei..d! Besides, you don't want to end up as a cowtaur :P

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Now I need to go ask that weird wasabi woman a Photoshop question... I wonder if she reads the newbie section...

 

Weird Wasabi Woman. Sounds like a hippie folk song from the '60s to me for some reason.

 

WWW

 

I like it! We should refer to her as Nancy "WWW" Gormezano from now on... see if she notices. ;)

 

-vern

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Weird? Vern is calling me?... Moi?... WEIRD?

 

Hmmm....I like it.

 

Well, actually all my little...ahem..."voices"... like it. We took a vote. Except for EVIL wonder woman. She's still thinking....very very bad thoughts.

 

Pssst, Gorfy Guy...I'm a fake...Vern is a true photoshop expert, and probably even that Eric "two forum named" Camden fella...Ask them any question...they are sure to make up something.

 

I would make up something too...but I would only lead you down the path of laziness and imprecision ...They, on the other hand will lead you down the true path of compulsive perfection and will have you manipulating pixels with a microscope and tweezer in no time.

 

BEWARE. But ask your question anyway.

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-Smooth splining is tough but as you practice you will understand for urself how things flow... things like spline connection/spacing (from one row of splines to another)/A row of splines in either direction can affect smoothness in the middle......it's important that as you model you pay close attention cuz this is not like other methods of modeling where you can just model care free, alot of planning is needed....

 

Good luck...

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Just a heads up, be very nice to Nancy - Wasabi woman. She is very skilled and very creative, not wei..d! Besides, you don't want to end up as a cowtaur :P

;) I know she's very nice - more "unique" than "weird" :wub: . I'd already implied that Vern was weird, though, and didn't really want to single him out. (But he is, though - isn't he...)

 

What is a "cowtaur"?

edit: Never mind. Just found a pic... :blink:

Boobs and udders- redundant backups in the mythological world, nice.

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Argh - replied to Eric without realising there were subsequent posts on another page.

 

I can't find the category where a photoshop question should go, so I'll ask it now. It's not really off topic...

 

Is there a way to gradient fill irregular shapes in photoshop? I want to apply a displacement map (I think that's what I need*) to a shield. The design is fiddly, and too small to be modelled so I think that making a greyscale image would be best. The design has five-point stars in it, like the brass ones you'd get on an Admiral's shoulder boards. These are surrounded by raised circles.

 

The closest I can get is to draw the shapes, then select them with the magic wand selection tool with a "feather" of a few pixels. Invert the selection, then press "delete". The feathered part then becomes a gradient to the background colour.

 

It's quite fiddly - is there an easier way?

 

 

* Am I right in thinking that a displacement map is really a bump map on steroids, in that the raised surfaces really are raised and can be seen from the side?

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I replied to you question in the other post, so I won't cover that again here.

 

Inreverse order:

Yes- you could think of Displacement and Bump maps on steriods. Bump maps only fake the shadow (and I believe the specularity, but not sure)

 

No and Yes - An easier way to create in PS I don't know. see your other post for suggestions on creating the Bump map (or maybe normal map;)

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Seeing how this is a thread about smoothing splines, I have a question too.

 

First to Vern,

 

Thanks for all that input. I've always wondered how you super modelers created stuff and the methods you put forth are great to know.

 

OK,

 

I'm not working on this now because of my commitment to "SO" but it's been bugging me for a while and since this thread addresses it, I figured I'd see what the masters say....

 

I hope Stian and Al respond as well.

 

 

Here's the Robot from the Lost in Space show.

 

robot.jpg

 

Here's a quick version of the robot.

 

robot2.jpg

 

This isn't in porportion it's just for reference for my modeling question. How would you cut in the holes for the arms, voice box and controls?

 

robot3.jpg

 

Everytime I try to model the cut out, it makes either serious dents or loses the shape.

 

Thanks,

George

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Here's the method I typically use to cut holes in convoluted surfaces. The steps are keyed to the attached screen grabs.

 

1. Cleverly lay out the splinage in your target surface with the foreknowledge of where your going to cut the hole. In this case a cylinder with enough radial and vertical cps to keep the required five point patches as small and symmetrical as possible.

 

2. Draw the outline cross section of the hole you want to cut using cp's that only coincide with existing splines on the target surface.

 

3. Move the hole's cross section cps so they all lay in the target surface. Tweak the appropriate mags and bias so its' splines also lay in the target surface.

 

4. Add extra cps to the splines in the target surface to match those in the cross section. Adding cp's to the circumferential spline will naturallly cause distortions that need bias correction.

 

5. Stitch the cross section to the cylinder.

 

6. Remove splines and define the five point patches. The spline ends on the broken circumferential will need bias tweaks.

 

Are the results boolean perfect? No. You'd need to increase the spline density to further reduce the size of the five pointers to eliminate the slight distortion near the edge. However you're likely to add edge moulding that will distract the eye of the beholder.

cylinder_with_hole.jpg

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Also, if you hold down the shift key while adding a cp the spline you are adding it to wont get distorted

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Thanks for the explaination Rodger. I'll try that the next time I get the chance.

 

Thank you also Masterfunk.

 

George

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Hi George

Here is a sample of how I would solve it. Keep in mind that the proportions are not correct, it was just a quick test. However, since I am bad at explaining stuff, I'll just add a render, wireframerender and the model for you to examine. I did break up the model in smaller parts to speed up the modeling and to make it less complicated to make. Hope this helps :) Feel free to do what you want with it

 

lostinspace0.jpg

lostinspacewire0.jpg

lostinspace.zip

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Is there an established technique for smoothing the surface of a model without each tweak of a CP affecting all the others that are linked through splines?

 

I've made a helmet which could do with being perfectly smooth, but has ridges as a result of modelling the nosepiece and eye-holes.

 

Did you spot the helmet in last month's contest?

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Is there an established technique for smoothing the surface of a model without each tweak of a CP affecting all the others that are linked through splines?

 

I've made a helmet which could do with being perfectly smooth, but has ridges as a result of modelling the nosepiece and eye-holes.

 

Did you spot the helmet in last month's contest?

 

So you did the Judge Dredd, Gorf? I got a kick out of seeing that. They reprinted the old Brian Bolland Dredds over here when I was in high school and I loved them.

 

An answer to one of your previous questions (sorry, didn't see it at the time), about doing an irregular gradient fill in Photoshop. If you have the solid fill on it's own layer, you could use one of the layer effects (inner glow, emboss, etc.) to get that effect. If you've got Illustrator, you could build it up as a blend.

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Hi George

Here is a sample of how I would solve it. Keep in mind that the proportions are not correct, it was just a quick test. However, since I am bad at explaining stuff, I'll just add a render, wireframerender and the model for you to examine. I did break up the model in smaller parts to speed up the modeling and to make it less complicated to make. Hope this helps :) Feel free to do what you want with it

 

lostinspace0.jpg

lostinspacewire0.jpg

lostinspace.zip

 

Wow!!! Thanks Stian. I really appreciate you taking the time to help me on this. I will be studying your spline layout. When I get a little more time I'll post my version of the robot.

 

Again Thank you very much!

 

George

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So you did the Judge Dredd, Gorf? I got a kick out of seeing that. They reprinted the old Brian Bolland Dredds over here when I was in high school and I loved them.

Yep - I liked the McMahon and Belardinelli Dredds, too. The Lawmaster bike model, and (though you can't tell from the contest entry) the Lawgiver he was carrying were both based on schematics published in the comic, but Dredd himself was a combination of all the early reference material I could find - except the shoulder, knee and elbow pads - they were rushed through as the deadline approached.

 

 

An answer to one of your previous questions (sorry, didn't see it at the time), about doing an irregular gradient fill in Photoshop. If you have the solid fill on it's own layer, you could use one of the layer effects (inner glow, emboss, etc.) to get that effect. If you've got Illustrator, you could build it up as a blend.

Thanks for that - I'll try those out when I get time (not sure I understanmd the terminology fully). The orange buildings in the distance were just JPEGs. The nearer buildings and the skyway were simple models whose faults were hidden by the "depth of field" setting...

 

(Edit: Added schematics)

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post-1449-1221349525_thumb.jpg

post-1449-1221349566_thumb.jpg

post-1449-1221349579_thumb.jpg

post-1449-1221350041_thumb.jpg

post-1449-1221350073_thumb.jpg

post-1449-1221350099_thumb.jpg

Edited by Gorf

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Gorf,

Your Judge Dredd was immediately recognizable. :)

 

A bit more work on texturing and lighting and that scene would be over the top!

I hope you'll return to that project and finish it off.

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On 9/14/2008 at 2:38 AM, Rodney said:

Gorf,

Your Judge Dredd was immediately recognizable. :)

 

A bit more work on texturing and lighting and that scene would be over the top!

I hope you'll return to that project and finish it off.

Just about to return to it, after a decade away from A:M

Just need to find an install disk :(

I just got a 3D printer and want to print something I created myself...

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How cool to see you back, Gorf!

Since you are back... you might be interested in... Prehistoric!

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On 10/7/2019 at 2:10 AM, robcat2075 said:

How cool to see you back, Gorf!

Since you are back... you might be interested in... Prehistoric!

Absolutely interested in that! Before I was in my teens (over 40 years ago) I was a walking dinosaur encyclopaedia. Now I'm just a dinosaur.

Couldn't find an install disk other than A:M 97 so I applied for the trial period just to see how much A:M has changed in my time away from it, but nothing came of that. Does the trial period even work?

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