3D Computer Graphics Using Blender 2.80 - Modelling Methods, Principles & Practice

          Blender Tutorials: 608 Bearing - part 10

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Part 10 Creating a Page Template


Before we go into the process of laying out the drawing view’s, an understanding of Blenders camera is needed.

Perspective Projection

The two images we have created in Part 9 use the camera in perspective projection mode and gives similar results, as you would get if an actual bearing had been photographed.

The size and shape of the image on the image plane is a product of the focal length of the camera, distance of the object from the camera and the object size. This type of camera will never give us the flat-scaled 2D drawing required.

Perspective View

Orthographic Projection

Blender includes however an orthographic mode for the camera, which takes a parallel slice, the size of the image-plane through the 3D workspace. The size of the image plane can be set to suit the overall size of the drawing you need to output.


The next thing we need to consider is the printer. For engineering purposes we are most likely working to a scale of 1 Blender unit equals 1 millimetre and the output from the camera is likely to be in 96 DPI (dots per inch) The usual output from a printer will be 300 DPI. So how do we get a drawing to scale out accurately onto a printed page?

Setting up the Scale

The way I find easiest is to set the camera scale at a multiple of 25.4 and set the size X and Size Y in the Format panel of the Render Buttons to an equivalent multiple but this time of 300. So if you wanted to have a 1:1 scaled image fit onto an A4 page of 11” by 8” you would need to set the camera scale to 25.4 x 11 = 279.4, the Format panel Size X: to 8 x 300 = 2400 and Size Y: to 11 x 300 = 3300. There is one further requirement as the image is set to print at 96 DPI not 300 DPI. This requires the use of an image-editing program such as the Gimp or Photo Shop, to change the output size of the image to 300DPI.

If you want to set your page up to print at an exact size and at a scale other than 1:1 the correct Camera scale factor and output resolution become a little more difficult to set up. The easy solution is to scale your model once you have set the camera to suit the page template.

Page Template

Save anything you currently have open Ctrl W and open a new Blender file Ctrl X. We will start by making a page template to suit an 8 x 11inch page, in front view add a Plane SpaceBar Add>Mesh>Plane, select and grab the top two vertices moving them 277.4mm (25.4 X 11 inches - 2 the original Plane size) in the Z axis. This sets the height of the page. Grab the two right-hand vertices and move them 201.2mm (25.4 X 8 inches - 2 the original Plane size) in the X axis, to set the width of the page. Select all vertices and delete X Only Faces to remove the face. This rectangle becomes the page boundary we need to work within. In the Links and Materials panel, rename OB:Plane to OB:A4pBoundary. (A4p being page size A4 Portrait)

Camera Rotation Next we will set the camera to view this rectangle at the print resolution.

Press N to open the Transform Properties panel. Change RotX:, Y and Z as indicated.

The Camera will now be parallel to the plane.
Camera Settings In the Camera panel (Editing Context Buttons) press Orthographic. 
Set the scale to 279.4 (11 inches x 25.4mm)

Format Settings
In the Format panel (Render Sub Context buttons) set sizeX: 240 (8 inches x 300 pixels) and SizeY: 3300 (11 inches x 300 pixels)
Camera View Select the camera and in camera view NumPad 0, move G the camera so that the outer dotted line aligns with the A4pBoundary.

Page Border Select the A4pBoundary object RMB and copy it Shift-D then press Esc to leave it in its original position.

Tab into Edit Mode and in edge select mode select each edge individually and move it G 12mm towards the centre of the rectangle, constrained to the X or Y axis.
Extrude Line Width
This rectangle will form our page border, it could now  be rendered as a wire object but the output will only be one pixel wide, so we need to thicken the line.

Select the Left hand edge and extrude it -0.5mm on the X axis. Extrude the Right hand edge 0.5mm on the X axis. Box select the three edges making up the top of the border and extrude these 0.5mm on the Z axis and repeat this on the bottom edge but -0.5 on the Z axis.
Rename this object A4pBorder

Add Plane Tab into Object Mode and Add a new Plane SpaceBar Add>Mesh>Plane. This will be used to create the edge ruler's. Move the Plane to the bottom left corner of the A4pBorder and resize to X axis 6mm and Y axis 0.5mm.

Select all vertices A and copy Shift-D the vertices on the Z axis 10mm .
Copy Plane

This will form the marks for a ruler that runs along the outer edge of the border.

Grab G the two Left vertices and move them
on the X axis 2mm. then select all the vertices A.
Array Modifier
In the Modifiers panel click Add Modifier and select Array from the pop up menu.

The Array modifier will copy the selection by the number set in the Count: field and offset each copy.

Vertices repeated 13 times Set  Count:13, De select Relative Offset, select Constant Offset and set Y:20. The selected lines will be copied up the side of the border.

Tab into Object Mode and select A4pBorder object.
Tab into Edit Mode for this object and select one of the long bottom edges.  Snap the cursor to the edge Shift-S Cursor>Selection. 
The cursor will be repositioned in the middle of the edge. Tab back into Object Mode.

Select the Plane object and copy it Shift-D then press Esc so it does not move position. Set the Pivot Point to Cursor select.
Mirror the copied edge ruler Ctrl-M and accept "X Local".

Mirror Object

The Border rules will now be mirrored onto the right hand edge.

Select both border rulers and copy them Shift-D then rotate them 90 degrees R-90. These will form the top and bottom rulers.

Copy and position rule Select the A4pBorder object and snap the cursor to the object centre Shift-S Cursor>Selection. Select the bottom ruler and snap this to the cursor 
Shift-S Selection>Cursor.

In the Modifier panel, reset the Array count  to 9
Top rule
Repeat this on the top edge but snap the cursor to the top left vertex of the A4pBorder object (Edit Mode).

Join Meshes It may be necessary to adjust the position slightly to ensure the rulers are touching the A4pBorder object.

It doesn't matter that the rulers overlap the border slightly, as we will be using a shadeless texture.

With the top ruler selected press Apply in the Array Modifier panel. This will convert the Array into a mesh objects.

Repeat this on the other three ruler's.

Shift-RMB Select all the rulers and the A4pBorder Object ensuring the A4pBorder was the last selection and join them into one mesh Ctrl-J.
All thats left now is the Title Box
Title Box
Add a Plane object and move it just inside the lower right hand corner. Resize the plane to 0.5mm high by around two thirds the width of the border. The exact size will be dependent on the text fields you want to put in it. 
Copy Lines
Copy the plane several times in the Z axis at a height to suit your text. I have used 7mm for the small text and 10mm for the larger text. Form a space for the title box by shortening one of the lines.

Copy and rotate Line Copy one of the lines Shift-D and Rotate it 90 degrees. Position it on the 
right hand side of the Title Box and adjust its length to suit the horizontal lines.
Copy and reposition to complete the Title Box
Copy this edge to form the other vertical edges and resize them as necessary.

Join Objects Tab into Object mode and with the Title Box selected, Shift-RMB select the 
A4pBorder object and join the meshes Ctrl-J.
The Border and Title Box are now one object.

We now need to add a colour for the border.
Set Material In the Materials tab of the Material sub context buttons, I have set R, G, B to 0 for a Black colour.

Select the shadeless button
so the colour won't be affected by any lamps in the scene.

Name Material In the links and Pipeline panel press the small button with the car on it. This will give the Material an automatic name representative of the colour chosen. In this case Black.
Add Text
We now need to add some test to the Title Box. LMB click over the Title Box to set the cursor position. 

Font Panel
Press the Space Bar to open the Toolbox and  choose Add>Text, a text object will be placed on the view, but much to small to see. In the Font panel of the Editing Context Buttons change Size: to 10

to remove the word Text and type in 608 Bearing. Scale S 
and move G the text so it fits in the Title Box.
To add the same Black Material to the text in the Links and Pipeline tab, click the Arrow box to the left of Add New and select Black from the pop up menu.
Scale Text
In the Link and Materials tab of the Editing buttons change the name from OB:Text to OB:A4pText.

Copy Text

Tab into Object Mode and copy the text Shift-D to another area of the Title Box and Scale it to fit. Tab into Edit Mode and Backspace to clear the text, then type in the new text. Repeat this for all the fields of the Title Box

One further useful addition is to copy a text object outside the Boundary object and type in the camera scale, Format size x and size Y and the printer dpi.
In the Outliner you will now have a grouped list of A4p objects that can be easily appended into any .blend file you are working on

The settings needed for the camera will be appended along with the Border.

All that is left for you to do now is make more templates in different page sizes.

Finally save your work as PageTemplate.blend

<< 608 Part 9 Rendering Tutorials 608 Part 11 Page Layout >>

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