In a grid, what is the "Up axis" and why is it always disabled?

[arechsteiner]

I've been toying around with the Grid and Axis Manager, and I cannot figure out what the third axis, the "Up axis" is doing. I cannot find any configuration that actually lets me manipulate any of the fields, which makes me question its existence in the first place. Also, sometimes there is a yellow warning sign without any further explanation as to what might be the cause of the warning.

 

I've been rummaging through the help, but I couldn't find any detailed explanation.

 

Cheers

[gdenby]

This is an interesting thing you have noticed. I worked thru every variation I could think of in the grid manager. None ever allowed changing the up option, same as you experienced. I did some reading around, and it appears there are no kinds of axonometric grids where the up axis is anything but 90. I can only speculate. Perhaps there is a plan to allow the 3rd axis to be variable in future developments.

[Ben]

The Up axis is for when you tick "Create plane set"... which itself becomes enabled with appropriate two axis grids (such as isometric or trimetric).  It enables you to define a third axis (which conventionally is the up axis relative to the flat plane in a parallel grid projection). It can be customised for the "Two axis custom" grid type, but will be vertical for all other predefined grid types.

 

You can cycle through three planes that are defined by your three axis by using the ' (apostrophe) key. You will need the grid visible to see this.

 

So, in the case of trimetric, you'd get the top, side and front planes.

 

Note that the Up axis is used to define complementary parallel projection planes.  This is not going to become true perspective 3D at any point.

 

The yellow warning triangles next to the angle controls show you when your axis angles are too close together to form a grid. Currently anything less than 5 degrees will stop the grid being created.

[Blueprint]

I have just brought the Windows version of Affinity Designer and the seems to be a problem with accessing the '3rd plane' of an isometric (and others)  grid.

 

When I try and cycle through the various planes with Ctrl+' all it does is turn the grid on and off.

 

I can not seem to access the up grid view, like I saw in one of the Mac version videos tutorials. Am I doing something very badly wrong or is it a bug that is due to be sorted out?

[Jonopen]

When I try and cycle through the various planes with Ctrl+' all it does is turn the grid on and off.

use the apostrophe key on its own.

[JET_Affinity]

By way of example:

 

1. Set Units to Inches.

2. Open Grid and Axis Manager.

3. Turn on Show Grid.

4. Turn off Use Automatic Grid.

5. Click Advanced Mode button.

6. Turn on Show Grid.

7. Turn off Uniform.

8. Turn on Create Plane Set.

9. For Grid Type, select Dimetric. (Affinity sets to its default dimetric angles of 15 and 165.)

10. For Grid Type, select Two Axis Custom. (Affinity retains the previously selected angles, and enables the Up Axis fields.)

 

For a correct ortographic projection (projected scale), dimetric axes of 15 and 165 mean that the top surface of a cube is tilted upward at an angle of ~15.49 degrees. Measures along the left and right axes would be foreshortened by a factor of ~.73.

 

11. Set the Spacing of the First Axis and Second Axis to .73

 

The vertical axis would be foreshortened by the cosine of 15.49, which is ~.96.

 

12. Set the Up Axis angle to 270 degrees (-90)

13. Set the Up Axis Spacing to .96

14. Close the dialog.

15. Make sure Snap To Grid is on.

16. Pen Tool: Line Mode. Mousedown at one of the grid intersections and drag a line rightward along the grid to the next increment. Ctrl-click the white space to deselect.

17. Mousedown at the same grid intersection and drag a line leftward along the grid to the next increment. Ctrl-click the white space to deselect.

18. Switch to the Move Tool (black pointer). Tap the apostrophe key. (Affinity displays the right-side grid.)

19. Pen Tool: Line Mode. Mousedown at one fo the grid intersections and drag a line downward along the grid to the next increment.

20. Move Tool: Select the vertical line and snap its top end to the origin of the other two lines.

 

These are three axes, foreshortened to correct proportions.

 

21. Duplicate and move two copies each of the three axes to complete a dimetric cube.

 

...and so on.

 

JET

[Blueprint]

use the apostrophe key on its own.

Thanks for the help (both of you). It didn't help just pressing the apostrophe on its own, nothing happened. So I went to preferences and removed the shortcut for cycling through the planes and then re-entered it as apostrophe and it now works ok. So all's well now, not sure why it didn't work from the outset.