How to set polar coordinates?

Support Basics & Interface
1

In the Blender wiki user manual on page:

wiki.blender.org/index.php/Doc:Manual/Lighting/Lamps/Hemi

it says to set a sun lamp’s direction so it is in a polar reference of (135 degrees, 135 degrees). Trying out things in Blender as I read along, I cannot figure out how or where one can set directions in polar coordinates. Can anybody help me with this?

2

this is pre define in blender

and you cannot change this in ligh panel

the only alternative is use a spot light where you can set the beam widht in angle and the orientation inside the viewport

good luck

3

With the Sun lamp selected press N to show the Transform Properties panel. You can set location and rotation there.

Or press R to rotate the sun manually.

4

Thanks, RickyBlender. Now that you mention it, I recall that the
sum’s directions cannot be set. So, I gather that the instructions
in the wiki are bogus (probably ought to be corrected). So, one
has to use a spot lamp instead, which can have a direction set
by me. But, that does, however, still leave open my question on
how to set that direction using polar coordinates. Unfortunately,
organic, I know about the Transform Properties (KeyN), but that
shows things in Euclidean coordinates, not polar. Is polar actually
possible? Maybe older versions of Blender supported it, or why
else would it have been mentioned in the wiki? Still confused.

5

there is no polar coordina in blender only recftangular unless you use a special script which i have not reallyseen yet

so stay in with recdtangu coordinates no choice here !

mind you thre are some polar in UV unwrap but only for unwrapping
and you do have mapping which can map a cyulinder but this is more cylindrical coordinates then polar !

can you show pic of what you want to do
may be can help some more with that !

hope it helps

6

It shouldn’t be too hard to make a script for this. I’m not familiar with python and scripting for blender myself, but it’s just a matter of converting coordinates from spherical (I’m assuming you mean spherical and not actually polar coordinates) to cartesian

x=r*Cos[Phi]Sin[Theta]
y=rSin[Phi]Sin[Theta]
z=rCos[Theta]

7

Actually that is the solution you’re looking for. The coordinates given (135, 135) are easy to input, if you set the rotation pivot to the cursor, located at (0,0,0) and then rotate the sun around it (start with the sunlight positioned somewhere along the x-axis, pointing directly at (0,0,0), then input the inclination and then the azimuth.)

However, the inclination should be reduced by 90°, otherwise your sun will change directions during the process. You’ll see what I mean if you do it :wink:

Or, as Morio suggested, just calculate the cartesian coordinates, using his formulas. No need for some extra option if you ask me, and the info on the wiki is not wrong either. It does nowhere say, that you should input the coordinates as they are written down there. It’s just a convenient way to make the directions of the sunlight clear, as in real life.