When I lent my services to a collegue who was working on a film about 12 years ago, I was introduced to the world of cnc. I remember watching this huge machining centre milling out a slab of mdf and turning it into a fantastic set of gears. I knew that it would have taken me hours to achieve the same thing with traditional power tools. I decided then that I would invest in a cnc router for my own business Oxenham Design. At that time I could turn on a computer, but even to check email seemed like a crazy set of operations. I persevered and learned every piece of relevant software I could get my hands on. I am now fortunate enough to be using Vectric's ASPIRE software, and Techno cnc routers, which has helped us to create some amazing projects, both in part, or in full. I thought that this blog would be a great place to share "behind the scenes" adventures with the software, materials and equipment we use, as well as the projects we build.

Sunday 26 February 2012

Setting up usable blueprints in HEXAGON

As we are in the midst of moving the shop, and nothing can be built,  I thought I would post a tutorial on how I set up drawing blueprints in Hexagon. I am writing this under the assumption that you will have a basic knowledge of Hexagon and some of its tool-sets. If Hexagon is a complete mystery to you, you can find some great tutorials here:

 http://www.cgdreams.co.uk/hexagon_vid/





This will be a lengthy tutorial for anyone not interested in modelling in Hex. For the people who are interested, let's get started!

Hexagon comes with a basic set of drawing planes ready to go, but this can be almost useless for multi images that absolutely have to line up PERFECTLY, unless you want to start cutting the image up in a photo-editing software.

As I am mostly self taught at 3d modelling, I'm not going to say that this is the best, or only way by any means, it's just the way I have adopted. Again, it works for me!

The first step is to get some blueprints for something you want to model in 3d. There are so many places that offer these, they're everywhere, and alot of them are free. Woo-Hoo!

I found a set at http://www.pixelcarart.com. Let's get a little 'Smokey and the Bandit' on this one!

I opened the image in Photoshop, to get a height and width measurement of the image. It was 9.542" X 4.528" You could use any image editing software for this.


The first step is to select the 'cube' primitive from the primitives menu at the top of the UI.
 Drag out a cube in the workspace. Any size is good at this point.

 Enter the dimensions of the image into the size boxes in the 'Properties' tab at the top right of the screen. Make sure that the 'Keep Ratio" box is un-checked, this will let us change the sizes non-proportionately.
Delete all the faces except for the back piece. This is the one that's going to get our image placed on it.
In the 3d modelling world, this is referred to as "uv mapping". It basically assigns image pixels to the geometry we just created.


 If the 'MATERIALS" docker on the left hand side of the screen isn't open already, select the arrow icon, and it will pop open (1). Now we need to select the "UV AND PAINT" tab at the top of the screen (2). This opens all our mapping and painting tools. Navigate over and select the 'planer projection' tool (3).



  From the drop down menu, select the 'texture image' option. 


 You should get an 'open' file box where you can navigate to your blueprint image saved on your computer.

 Your image should now appear on the rectangle polygon we created. If your image comes in upside down, or backwards, try checking the 'flip vertical' or 'flip horizontal' check boxes until it is facing the right way.

The last step we need to do is to "VALIDATE" the operation.




Now we select the "SELECT OBJECTS" icon at the top of the screen. Now that we are in 'objects' mode, select the image plane, then copy and paste it.


  Using the handles on the universal manipulator, rotate the copied part 90 degrees to the original part.


This will become the "TOP VIEW" of our 3d blueprint. If you hold down the shift key while rotating the part, it will snap at 45 degree intervals. You can assign numerical rotation values as well in the "PROPERTIES" docker on the right side of the screen

Use CTRL+V to paste in a third copy. Again, using the universal manipulator, rotate the drawing 90 degrees. This becomes the front and rear views of the blueprints.


ALIGNING THE DRAWINGS

If you only rotated the the bottom copy, they will already be lined up. You can double check this in the properties tab, under the 'position' section. Both of them should have the same number in the red box.

Now select the side plane and move it into location using the manipulator. Check size and alignment all down the length of the car. Once it is aligned, ONLY move it on the red or green direction. You don't want to mess up your new alignment!


These are the aligned views after you have spent some time tweaking them in x-y-z-space.

And that in a nutshell is how to align blueprints.
Post any questions, and I will hopefully be able to answer them
8)
JO

2 comments:

  1. Once all the images are aligned how do you proceed to make the 3D model? Just start by creating a block and edit it to match or is there some magic method that trims based on the bitmaps?

    ernie

    ReplyDelete
  2. No, I basically start with a block, and start extruding it outwards. Adding edgeloops etc. It can take a while depending on what your trying to make. some models can take up to a week to finish, depending on the detail.

    ReplyDelete