View Full Version : How can i mirror nurbs curves and surfaces?

08 August 2002, 01:25 AM
Hi guys, im new to maya and i am curious if is there a way to mirror nurbs surfaces and curves...right now i have to convert to polygons to mirror...


08 August 2002, 02:25 AM
There is no need to convert your NURBS geometry to polys and then use the mirror faces technique.
Take the centerpoint of the geometry (Nurbs patches or curves in this case) and move it to the 0,0,0 point in worldspace. The duplicate the geometry with the correct offset of -1 (usually in X) scale. That will solve your problem, You dont need to use a mirror tool at all if you locate things at 0 Worldspace.

I recommend taking a class or two to get yourself into MAYA, its a hard program to start off in and instruction is probably what you need.

08 August 2002, 05:57 PM
Thanks for the tip dmcgratth, two months playing with Maya/and his manual... amazing tool, a lot of cool stuff. Unfortunely we dont have this kind of help here in Brazil (yep, im from Rio de Janeiro/Brazil) only 3dsmax, so i have to learn for myself... right now coursing Industrial Design in UFRJ(local university) and be thought to use Solid Works :(

Thanks for the pic! nice shot!

08 August 2002, 06:11 PM
remember: its all about the pivot! you can control the ''god''pivot by hitting the insert key to move it!


08 August 2002, 06:29 PM
here is a nice script - drag it in ure shelf

//Mirror script ... ovvero quello che mancava a Maya fino ad oggi !!! =) by Leonardo Bruni
//Copyright Leonardo Bruni from Digital Explosion

string $Clr;
string $NwRotPvt;
string $NwSclPvt;
if ("window -exist $MyWindow"){deleteUI -window $MyWindow;}
window -title "Mirror Tool v.1.0";
rowLayout -numberOfColumns 3
-columnAlign 1 "left" -columnAttach 1 "both" 0
-columnAttach 2 "both" 0 -columnAttach 3 "both" 0;
button -label "X_Axis" -align "left" -command "move -a 0 0 0 $NwRotPvt $NwSclPvt ; duplicatePreset(1,1,1,0,0,0,0,0,0,0,0,0,1,1,-1)";
button -label "Y_Axis" -align "left" -command "move -a 0 0 0 $NwRotPvt $NwSclPvt ; duplicatePreset(1,1,1,0,0,0,0,0,0,0,0,0,1,-1,1)";
button -label "Z_Axis" -align "left" -command "move -a 0 0 0 $NwRotPvt $NwSclPvt ; duplicatePreset(1,1,1,0,0,0,0,0,0,0,0,0,-1,1,1)";

08 August 2002, 07:20 PM

wow!, fast replys, you guys r great!

graphiouz, do you know how to rotate the pivot? i know how to move it (insert key) but i cant rotate his axis...right now im working on a aircraft model, trying to pull down the landing gear...the problam is when i try to open the faces (that keep the gears indoor) they dont open correctly or rotate in the right direction(axis).

Swag, thanks for the shortcut, vary nice script!

08 August 2002, 07:55 PM
(To my knowledge) rotating pivots in Maya is something you can't do very easily, but there is a workaround.
You need to parent the thing you want to a locator, and then use the locator as the pivot of the thing.

Not the prettiest fix, but it works... usually :)

08 August 2002, 07:56 PM
This is very easy as well. Ill show you what I did with the hatch in my Above and Beyond challenge. Give me a little while and Ill post another something for you.:wip:

08 August 2002, 09:05 PM
On rotating objects in your scene...
The important thing is in how they are grouped into your scene.
Below is a pic I made trying to illustrate this point.
I have all of the objects parented under the main trapdoor.
The pivot of the trapdoor is located (by convince) at the hinge in the bottom left. I have set it up this way by using the insert key, that you are already familiar with. Now all I have to do is select the door, and use the rotate (red circle bottom left) handle.
I hope this helps a little.
Remember that you can parent anything you want under anything else. When you move rotate or scale the parent, everything else is also affected. If you parent the landing gear to the plane, for example, you can move the plane anywhere in your scene and the landing gear will stay with the plane.
Does that make sense? Here's the picture.

08 August 2002, 01:38 PM
sorry for late reply guys, writing this on a coffe shop machine, im having problams with my intranet...

i wanna do picture to show you guys my problam...let me see...yep i found it! Paint for windows...a pro workaround...

08 August 2002, 01:52 PM
dmcgrath, when i got home i will try play scale and ratate with parents, i alrady did a lot of things in the outliner, i try to group the construction curves and faces under groups to make easy identify the objects... the bomber, background and landing gear animation is almost done with the model, working on textures and lightining... playing with dynamics (rain) and expressions(intensity on some lights to make them flash)

when i got home i will try to upload a picture of my project and you tell me what do you think... :)

08 August 2002, 07:05 PM
Yeah I'm sorry, but I am still having a problem understanding what you want to do. You are rotating just one face of a polygon? Or are you trying to flip the normal? Instead of keeping the polys attatched to the plane, use edit polygons-->extract. It creates a new surface from the selected faces by cutting them off of the large poly. Then you can group them back under the plane as seperate pieces.
Good luck on your internet.

08 August 2002, 08:01 PM
or is it another object, say a plane or something.

I understand what you want to do. heres what i thought.

if its a subobject, you can change the axes between local and global mode (check out the tut about making a hammer using polygons by pressing f1 key in you maya).

If its a different object all together, try reset transformations. once when i encountered this problem, it worked. also check if the plane is subject to any constraits. so if you explain what constraints or there, or if you can explain it more, I can help you more i hope.

I am no where an expert. I am just a beginner. So, sorry if any thing mentioned didnt work. I was just trying to help. but if it works, do post it up.
I suggest you just create these objects once again cleanly with axes aligned properly.

08 August 2002, 01:10 AM
hey guys, thanks for the replys :), probably someone alrady answer my problam... i will check tomorrow, if i make it, i let you know it.

dmcgrath, here is some pictures to help you see the problam...

d_jnaneswar, i will try what you said... any help is wellcome!!!

-wT-, i think you understand the problam...:)

and for last, one of my test images, what do you think guys? critics? sugestions? if you like i can post a larger image...

08 August 2002, 01:12 AM
i hope it helps...

08 August 2002, 01:15 AM
another one... the same problam with a different exemple, trying to flip the tail's flaps.

obs:. sorry for my english :)

08 August 2002, 05:22 AM
The need of yours, is just to get the flaps to go up and down, as well as the landing gear doors to open the correct way. Yes?
I gave you another picture, hopefully this one shows you what you need.
In pic 1. I made a quick wing to help you along. This is barely more than a small polygonal box as the rudder.
In pic 2. I moved the pivot for the object to where it is supposed to pivot on a plane's wing.
pic 3 and 4. I can now rotate the object up and down in one axis (X axis on my example) for convience.
If the rudder is parented under the main wing, you can translate or rotate or scale the wing all you want and the rudder will ALWAYS follow it.
No matter where you go the rudder will never have to move in any other direction than on "its" X-axis.
I am sure that this is what you need to do, you can do the same thing with landing gear as well.
You can temporarily move the pivots of faces or cv's when you select them and hit the enter key, but I dont think that is what you want to do.

Good Luck


{By the way, no one should ever have to apologize about how poor their English is, you should hear my Portugese.}


09 September 2002, 04:45 PM
you want to open that door kind of thing below the plane right.

If I were to attempt that, I will do it by taking a small box, i would model each door and then place them there with pivot at the hinge point. place a nice locator there with setdriven key set to the rotation of the doors. That way, there wont be any problem of pivots(because of new clean objects instead of faces)and i would be able to use set driven key to animate them easily.

I hope it worked.

09 September 2002, 04:51 PM
why dont you go to subobject mode and just adjust vertices so that they allign properly with the pivot? and then rotate it to fit where you want?

This should definitelywork.

09 September 2002, 01:15 PM
Um...surely you just double-click on the rotate button, and select 'object' or 'local' transformation?

Remember an object is never transformed, its local frame is transformed. Doing 'world' transforms actually requires more steps than doing 'local' transforms as you have to align the object's local frame with the world frame before you do your rotation.

09 September 2002, 12:07 AM
yeah, it just depends on the reltionship of components in object's local space to its local axis is, which may or may not align along the 'logical' axis of that the construction of your components suggest. so, if you dont want to add another transform (just grouping transforms to themselves ..or with a locator as a visual aid, as metioned above), do as d_jnaneswar mentioned last - move the components in the local space to realign them with the local axis as you see fit. grab all of the components when you do this (by simple selection, or using a deformer, whatever). alternatively, you could use the rotate axis offset, which, funnily enuf, offsets the local rotate axis. once you get the hang of this you can setup methods to make altering this local axis a little easier.

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