Question About the Scaling?



First of all, I’m really enjoying the tutorials. I have a question about the final 2.6 scale factor that was applied to the sphere.

If the target diameter is 21.59 to 21.83 cm, should the final scale applied to the sphere be somewhere between 2.159 and 2.183? It seems like the 2.6 is outside the target diameters.

Also, since the scale applied to the sphere seems to be working on the radius, not the diameter, I would think the final scale applied to the sphere would have to be between 2.159/2 and 2.183/2.

Sorry, if this seems trivial but I was just starting to get my head wrapped around the model to real-world scaling thing. During the challenge, I applied a 1.085 scale to the sphere which, I thought, would give me a final diameter of 2.17 blender units which then would real world scale to 21.7 cm.

Any clarification to my misunderstanding would be greatly appreciated. :slight_smile:


glad im not alone, if i remember correctly the bowling pin was 38cm so we made it 3.8bu (remember we moved it up 1.9 to make it sit flat) so if a bowling ball is 21.59 to 21.83 then it should be a object 2.159bu to 2.183bu meaning that your scale is correct.

thank you for validating my WTF moment.


I had the same problem. I made mine at 2.16 Blender Units.


Okay. I have redone the whole process from Lecture 53 through Lecture 55 and cannot duplicate the Bowling Ball as seen in the video. I use the same specifications, 4 subdivisions and I get 642 vertices. The video shows 1,124 vertices. If I change to 5 subdivisions I get 2,562 vertices. The placement of the holes is based upon the number of faces and vertices, so I cannot duplicate the whole process. I cannot figure out what I have done wrong. I realized the scaling problem after viewing the following Lecture, Lecture 56 is a mistake that can be corrected.

How do I get the same size and number of vertices and faces that are in the video?

I am using Version 1.78 if that is a possible cause.

Anyone have a solution?



I have the same question… I use 2.159 BU (21.59 cm) … and I dont understand why the teacher had used 2.6 BU (26.00 cm) …


“WTF moment”… hahaha looks like me here trying to realize where I got lost… hahahahah


Actually now that I see this post I was wondering the same thing. Would be nice if someone could answer this. Still, I went with that weird scaling without wondering why because I thought “maybe I missed something and I did something stupid” and went on to the next lecture.


The teacher correct this issue in the next videos … he said "ops, my mistake… " and correct the scale… :wink: :smiley:


perhaps it is the extra objects in the scene. icosphere uv sphere etc.


Related to all of this - and I echo comments from others about enjoying the course so far - I’m really confused about the scaling thing. If we were working in cm for the Pin and the Ball, why wouldn’t we just change the scene scale in the Properties window to cm…? Doesn’t that make BUs 1cm rather than 1m? Would they come out the same size then?

I’m just a bit confused why we’ve touched on the scale section in properties if we’re not using it.


Yup, echo all above, I had come up with a scale of 2.16 (radius 1.08) as well. TBH I found the whole discussion on scaling especially what we were actually doing when scaling the image, completely confusing.


My ball is also 2.16 or 1.080 radius.
So I guess everyone in this post gets it :smiley:


Well, I looked at this post before I continued the video, same as everyone else 1.08bu


This scaling business is driving me nuts!

I assumed a ball was 22cm to make the maths easier.

So lets say 1BU =10cm,
to fit 22cms into 2BU, we need to scale the cube/sphere
by 22/(2 x 10) =1.1

which is close to the 1.08 others have been getting.

After struggling and re-watching videos and re-reading my notes, I read there is a mistake in the video!!!

Come on guys - please, for the sake of those who come after us could you please either edit the video or better still, remake it in it’s entirety and then you could also make it clear in the Challenge that we are to use one of the spheres already created.


Looking ahead, I will tell you the truth - I did not understand then with these mathematical calculations) but! if you simplify a little, take centimeters, it will become much clearer, or another example - 1 BU is equal to 1 meter, which can be seen in the game engines, everything is taken with respect to something. For example - if you make a wheel for a car of size 1 BU, then the body will be clearly more about 5-6 times. Another example is making a chair, pushing away from 1 BU, then the table will be about 1.5-2 BU, or rather you can again take the familiar value. Of course, if you make models in different files, it will be more difficult to compare their sizes.
This is just my vision. I do not pretend to be true, everything is relative, but the desire to do as shown is sometimes stronger :sweat_smile: