Advice on how to proceed with model

TimVukman

Hi:

I suspect that I am trying to do this in a more difficult way than I should. I am trying to model an F-14 to learn Hexagon. I have reference diagrams, but I can't get them to line up with each other by putting them in the grid planes of the bbox. In other software I was able to adjust the position of the diagram on it's plane, but I see no way to do that in Hexagon.

Since that didn't work, I made cross pieces as my diagram showed their profile at various points along the length of the aircraft. I thought I might be able to run a line from one to the next in order to attach to the frame members and create a skin around the plane. That's not efficient and it will take me forever. Also it next to impossible to line up as I can't seem to weld a new line that exists in free space to a frame member even though they are both made of points that are visible.

I tried a cylinder with many sections and I really made a mess trying to fit the cylinder around each of the frame members.

1. Can I adjust the location of my reference diagrams?

2. How can I join two point based entities? The first is a loop of points which is the frame member and the second would be a line or square or something to go between frame members as a skin.

If I should scrap what I have and start over with a different method, that would be fine too.

thanks,

tim

Roygee

Hi there :)

First off, what you are attempting as a learning exercise is very complex - maybe start smaller and work your way up?

If you want to dive straight in to the deep end, let's start with getting your reference images lined up. Are they from a single blueprint, where you have to cut them up into top, side and front/back views, or are they separate images? Are they all to the same scale?

There are two methods to get your images lined up - one is to map them onto planes and line them up physically and another is to place them on the grid. I can give you more detailed advice if you give answers to the above - there is also a very good tutorial at Geekatplay on how to do this. It is the tutorial on modeling a car, which was never completed, but he does give detailed advice on lining up reference images.

I'm not too clear on what method you are using to make the fuselage - using surfaces is my favorite method - make a circle, line it up and scale it to fit the reference image, then copy/paste and move along the length, scaling each, then use ruled surfaces to join them up as a mesh.

In order to weld two lines/curves, you need to have the end points of each in exactly the same position in 3D space. You can do this by copy/pasting the XYZ coordinates of one end point to the end point of the other curve, select both curves and weld.

TimVukman

Roygee said:

Hi there :)

First off, what you are attempting as a learning exercise is very complex - maybe start smaller and work your way up?

Yes, Roygee, and thanks for your response. I have certainly figured out that this is very complex. I did find a way to move forward, but it is not the right way to go. I added thickness which turned my point outlines into tubes which I then collapsed and was in the process of welding points between my tubes to join the cross sections together when your note came in so I thanked my good fortune and quit.

If you want to dive straight in to the deep end, let's start with getting your reference images lined up.
Thanks!

Are they from a single blueprint, where you have to cut them up into top, side and front/back views, or are they separate images? Are they all to the same scale?
The cross sections were on the same sheet as the side view. The front and top views are on another page. They are all the same scale

There are two methods to get your images lined up - one is to map them onto planes and line them up physically and another is to place them on the grid.

I can say for sure that I do not know how to map them onto planes. I did place them on the grids via the property sheet.

I can give you more detailed advice if you give answers to the above - there is also a very good tutorial at Geekatplay on how to do this. It is the tutorial on modeling a car, which was never completed, but he does give detailed advice on lining up reference images.

Rather than tie you up, I will look for the tutorial. I may have a question or two after that, but it sounds like the place for me to start.

I'm not too clear on what method you are using to make the fuselage - using surfaces is my favorite method - make a circle, line it up and scale it to fit the reference image, then copy/paste and move along the length, scaling each, then use ruled surfaces to join them up as a mesh.

I used a multi-sided multi-sectioned cylinder which got out of control pretty quickly as I moved along the length. Thanks for your suggestion. I will try that.

In order to weld two lines/curves, you need to have the end points of each in exactly the same position in 3D space. You can do this by copy/pasting the XYZ coordinates of one end point to the end point of the other curve, select both curves and weld.

Thanks for this suggestion. That is an excellent idea.

Tim

Roygee

Good luck with your project - looking forward to seeing progress.

Don't hesitate to ask questions - we were all where you are now and got helped by others, so are always ready to help out :_

TimVukman

Thanks Roygee

I am editing a post which I had put here outlining some problems that I was having in getting the reference planes set up. I watched both of the recommended tutorials which were very helpful. I ended up with 3 planes, with UV projections, but somehow in the process my manipulator went from being 3d to being perfectly flat. I was unable to rotate the last plane with any success.

So, when in doubt, do it again.

I created a new document and redid the entire process from start to finish. Everything worked out properly and I now have my three reference diagrams in place, ready to start the model.

Thanks for the help

Tim

Roygee

Well done :)

I think I pointed you to the wrong tut - I personally don't like the box method for two reasons; one, when you need to go into wireframe, so does your reference and you can't see the image; secondly, Hex has a bad habit of flipping the images when you re-open.

I have all of Geekatplay and EZ's videos on disc - have to go out now, but I'll check this afternoon for the right one to project onto the grid.

Just a couple of pointers -first, I only ever use the universal manipulator; this is one of Hex's most powerful tools. Secondly, for precise rotations, use the rotate function in the properties panel, then use snap/align in the utilities tab to get the edges perfectly aligned. Thirdly, use copy/paste (Ctrl D) to copy.

Please keep us updated on how your progress :)

TimVukman

Hi Roygee (edited for spelling)

Thanks for thinking of me with additional information. The Geekatplay videos that I watched do indicate that they are going to use the box method. I have never done that, and the tutorials don't get to the point where the actually show how to do it. I have used my traditional model building method. I started with a cone for the nose and then I have been adding cylinders along the fuselage. Once the sections are lined up to the diagrams, and then to the previously placed section, I weld the points. I have been using the rotate in the properties panel as I did notice that any hand rotation might look ok but it was never the exact number in the properties panel.

After a cylinder is placed, I delete all of the faces on one side so that I am modeling half an aircraft. I usually join up a mirror image near the very end.

It would be helpful if you have a suggestion on how to smooth the fuselage along the length, or by selecting a certain group of points. I always spend a great deal of time aligning points front to back and in an out along the way. I add lines along the way as needed for features or details.

thanks,

Tim

StratDragon

I'm not a hex modeler, but I've modeled in blender, and while looking for your question I came across this and Johnny Bevo if you're reading this I THANK YOU MUCH for this even though I could not get Hex stable on my rigs and switched to another modeler entirely.
to add smoothness to a model you need to subdivide but there are some important things you need to know along with that and Jonnny can explain ti a million times better than me.

http://www.youtube.com/watch?v=YitxFzKE3K0

but to reiterate, your model of choice is super complex, you may want to model simple then come back when you know what to expect and know how to make the tasks easier and do it correctly.

Roygee

Hi Tim

Hope you have watched the video by Johnnybevo ? As always, very informative. This video pretty much describes how to keep some edges sharp while smoothing others.

I would need to see a screencap of your model as it is now - in wireframe - to see what needs being done to smooth it.

In general, you smooth edges (not points) by selecting the mesh and selecting a smoothing level in the properties pane, then collapsing DG. You should not need to go above level 2. Bear in mind the lesson in Johnny's video - there will no doubt be areas which need to be excluded from smoothing.

Don't fall into the trap of using smoothing to make up for poor mesh construction!

Just for information, I smooth as a very last step, even after UV mapping.

I've had a pretty busy day, so didn't get a chance to look for the tut on cutting up a blueprint - will see i I can fit it in tomorrow:)

TimVukman

Thankyou Roygee and StratDragon:

I have watched the tutorial by Johnnybevo and I am pleased that he took the time to make it and share it. I learned quite a bit from that and since I had never pressed the button for the smoothing, I was unaware of what could be done with it. I really like the break mode for designating edges to maintain sharpness.

I want to make a good mesh because I find that is the best assistant for being able to UV map effectively. I usually end up adding lots of edges between points as I model, part to match the reference diagram and partly to transition between different elements in the model.

I chose the F14 on purpose, because it is complex. I have modeled several aircraft in XSI Mod Tool in order to bring them into Crysis to use in animations of fly bys or ground vehicles, etc. If I choose something simple, I will not learn as much as I will learn by working through the complexities of something like the F-14. Yes, the F-18 would be easier, but I have already done that one.

Thank you Roygee for suggesting I smooth using edges. That might help me speed up my process a bit, but I don't want to try to rotate edges to fit the geometry. Points are much more flexible for me to model with although getting five or six lined up to effectively look like a smooth line is like herding kittens. Using the smoothing demonstration from Johnnybevo's boat example looks like it would make life easier, like lining up the points as if they were horses at the start of the race.

Either the Mod Tool didn't have the Fast Extract feature, or I didn't know about it, but I am using it alot to wrap a skin around my fuselage and create the flat areas around the aircraft. I am really enjoying the capabilities in Hexagon.

Tim

RedSquare

Thank you Roygee for suggesting I smooth using edges. That might help me speed up my process a bit, but I don’t want to try to rotate edges to fit the geometry.

I'm obviously thick! 'cause I don't understand the latter part of this. Where does rotate edges come from ? I don't feel Roygee was suggesting anything of the sort. :long:

TimVukman

Hi RedSquare

No, you are not thick. I was carrying an idea forward in my head. I should have left it there. If I have a row of points going horizontally along the fuselage, it is hard for me to line up the points so that they follow vertically and horizontally in a line without points either being "out" too far, or "in" to far where the skin of the fuselage would be the perfect spot. It may help me to line the points up if I smooth by edges as Roygee suggested. Perhaps a bad attempt at humour on my part to picture trying to rotate a horizontal edge to have it adjust the point at one of it's ends to where I want it. If a point that I want to move "out" is at the left end of the edge, and the right end is perfect, I would just grab the point at the left end and pull it out which defeats the point of using the edge in the first place if I am only using one edge between two points.

Thanks,

Tim

Roygee

I think i understand what you are getting at - a screencap would really help, though.

If you have a bumpy surface as a result of unaligned verts, as in the attached cylinder example 1, you could align them by selecting the edge loop to which they are attached and make the size on the appropriate axis 0 - see where the red arrow is pointing. This action results in straightening out the line, therefore the points, so that there is no difference between the points on that axis - see example 2.

Smoothing will not resolve that problem - all it will do is smooth out the difference, as in example 3.

Hi Red - long time... :)

TimVukman

Thanks Roygee:

I am having a problem with screen caps. I'm trying to use ScreenHunter 6 on windows 8 and it is putting up blank scene, properties and dynamic geography when I tell it to take a picture. No picture though.

Picture 1 would be representative of my starting point. For the purposes of our discussion, picture 3 will suffice. I would select each ring around the cylinder in turn and scale it vertically and horizontally to conform to my reference diagram as best as I could. The side of the cylinder closest to the "untitled_1" identifier of the file name would be what I am working with as a half of that cylinder. I delete the faces on the right side of the cylinder. I can't tell you how many times I have selected a point on the left side and welded it to a non related point on the right side, so I eliminate the right side. Let's take the yellow pointer on the universal manipulator as representing the row of points that I want to align along the blue Z axis. Imagine the same cylinder with the points as the selection item. I grab one or more points and adjust horizontally and vertically to contour the fuselage. I want them to form a smooth plane along the Z axis relative to the other points in the same row. I haven't tried, but could I maybe select the row of points and click on the smooth option to accomplish this alignment?

thanks

tim

RedSquare

@Roygee ~

Hi Red - long time… smile

Indeed, too many new software releases to learn; to few brain cells to accomplish. :lol:

Roygee

@Redsquare - same problem here..:)

Hi Tim - I've tried posting twice and got stimied by Daz's weird site behaviour - third time lucky?

Does your keyboard not have a printscreen option?

Seems to me you have a misunderstanding of the smoothing function, so I'll try a quick explanation.

What it comes down to is that there is no such thing as a true smooth curve in polygonal modeling - only straight lines - the shorter the lines, the closer we get to an impression of a smooth curve.

In the attached pic, the first "circle" has 8 side and 8 points (verts), so is not very round. The second has 16 points and sides, so is more rounded and the third has 32 points and sides. These were all made from the same shape, with 0, then 1, then 2 levels of smoothing(subdivision) applied.

What smoothing does is to divide each edge in half and average out the distance on the points on either side to give an impression of a smooth curve.

So, to answer your question, no, you can't apply smoothing to points, only to the mesh and it will not align misaligned points.

Pushing and pulling on verts in a cylinder can only lead to heartbreak:)

If you can post pics of the top and side views of your aircraft, I'll try to make a quick tut for you

Cheers :)

m_m_italy

RedSquare said:

@Roygee ~

Hi Red - long time… smile

Indeed, too many new software releases to learn; to few brain cells to accomplish. :lol:

:-)

TimVukman

Hi Roygee!!

I'm not sure why, but I did not get an email to tell me about your last post. If all went well, I have a screen capture from ScreenHunter attached to this post. I am perfectly clear on what you are saying. That is not what I was looking for. I am dealing with the distorted cylinder from your previous post. I think it is #3.

The screen capture here is the result of a mathematical approach to the problem. I created a spread sheet into which I place the X, Y, and Z numbers from the property sheet. I can start from the top or the bottom of the model, so let's use the 0 Axis as my example. If one of my cylinder devisions is running across the cylinder and therefore 90 degrees to the cylinder length, I know that the X axis for the numbers in the X of the property sheet will all be 0 since the line is set there.

What can get messed up, are the Y and Z values. The whole cylinder is not a complete mess, but there will be points that are out of alignment on the Y and Z axis.

So, if I start at the bottom of the model, I know that my X is 0, and my Y and Z are on a reference drawing and therefore should be positioned where they should be. I enter the X,Y and Z from the property sheet into the "Bottom" line of my spreadsheet. I skip one horizontal line and therefore land on the third line from the bottom. I enter the X,Y and Z from this point into the "Top" line of my spreadsheet. I add the x's to each other and divide by two to average them and then add this value to the bottom x value. I do the same for Y, and then for Z.

Once I have added the six numbers, my spreadsheet shows the values to enter into the property box for the point that I skipped. It takes a little time, but if I work my way through the point, I will have them all lined up into a clean skin on the fuselage.

(Added in edit) I have a

 tag before this example and a 

at the end. Why isn't the text in fixed format?

Example
                       X          Y          Z
Top            .58       2.846   -1.081 

Bottom      .58       2.739   -1.168

# to Enter  .58      2.792    -1.124

Formula  =    ((Xtop-Xbottom)/2)+Xbottom,   ((Ytop-Ybottom/2)+Ybottom,  ((Ztop-Zbottom)/2)+Zbottom

I have a slope across and along the wings to deal with, so I will note the highest point, and then the lowest point. If I set equal measured distances for a grid that covers the wing, I can mathematically calculate what the values need to be to get an even slope in both directions.

I have some photos that I can mark up with grids to see what the actual slopes are and hopefully I can determine the true slope angles to use.

I am also not doing the model in one shot. I have restarted with just the fuselage, and then I will do the basic body, next the engines, then the wing extension, tail wing and verticals.

I think I have an answer to my question that I can work with. I thank everyone for their input, ideas and help.

Can functions be built for Hexagon? I'd love to be able to enclose three consecutive points and have a button to push that will then tell me the numbers for X, Y and Z that I need to enter for the point in the middle.

Please post if you have any questions or concerns with what I am doing here.

Thanks

Tim

Roygee

Well, that is certainly a novel approach - glad its working for you :) Looking forward to seeing the completed model.

Pity there is no SDK available for Hex - it would be great if users could write plugins such as this to make life easier.