Ball stops at frame 10

[Grisgram]

i did exactly as you did in the video but my ball does not continue to roll…
it immediately stops at frame 10 and stays there.

is the handling somehow different in 3.1.2?

Frame 1: Press I → RotLocScale → Hover over the Checkbox Press I (it turns yellowish)
Then move to Frame 10 → G Y → Move the Ball → Hover the checkbox again and Press I

In 3.1.2 it looks like this

I had to open the summary tab on the left to get those yellow diamond markers - by default, they were not visible.

When I start the animation, the ball stops at frame 10.

What did i do wrong?

Here’s a short screen recording of what happens:

[Grisgram]

I hope i get a reply with some tipps - for now this is the first lesson i can not complete. no idea, what’s going on.

[Grisgram]

After a long series of (for me totally unintuitive) clicks and hovers and delete keyframes and startover, i could manage that the ball continues (but i have no clue, WHY - for me i did the same all the time… and suddenly, it kept moving)

but beginning with frame 11 the ball changes direction out of nothing - sometimes it flies up in the air, sometimes it drops down.
the alley is a passive body - but also the pin just falls through the ground… no idea whats going on here - the pin is not even animated!

[NP5]

The ball stopping is probably due to not animating the turning OFF of animation so the Physics system takes over.

I suspect the ‘flying ball’ will be related to the collision boundaries. Test the ball. make it start above the alley. Also make sure the Alley has no geometry higher than the plane the ball wants to sit on. Convex hull collision type uses a bounding box style collision shape so if any of the lane object is higher than the bit the ball is supposed to rest on that higher level is treated as the top mot the lane. Changing all collision boundaries to ‘mesh’ can solve such issues. Or fix the lane geometry to be flat.

If things fall through the same basic things, check they all have the rigid body on. Check they start a bit above the floor at least, just to test that is working. Again collision boundaries might affect the interaction.

General Q&A note
Help us all to help you.
Please give full screenshots with any questions. With the relevant panels open.
Also, include the lecture time and name/number that is relevant to the problem/issue.
This can be done by Blender itself, via the ‘Window’ menu bar top left hand side.
On that menu drop down is ‘save screenshot’.
Close ups additionally where they help.

Gifs help a little for moving things but are impossible to freeze or enlarge, they are ‘additional’ to informative full screenshots on the whole.

[Grisgram]

Thank you very very much for this detailled response!

I started all over, deleting the file and starting with the final render scene from the previous lecture (only good, i create a “Save as…” for every lecture) – just to make sure, I did not confuse some internal data structures in blender due to all my experiments.

After doing some tests I found out, that the problem is the big object that surrounds the alley - the two half-cylinders on the left and right and the cage at the end, where the pins should drop in.
If I give this object a passive rigid body, the entire physics engine runs mad.
So I’ll fake the cage and floor with simple planes that shall hold the ball and pins back - but I think, I messed something up with that object…

see this image - it’s one large object containing lots of extrusions, merges,bevels and so on…

as long as this is not part of the physics game, everything runs fine.

[NP5]

Well done, it sounds like you have sorted it out. It will be that highlighted old lane that was a lot of the problem as its bounding box will be the full height all round the whole object. Faking it with false a floor that has the physics on it is a good solution.

[Grisgram]

i think, this bounding-box thing (though i am very used to GameMaker and Unity) was the biggest learning-curve here … the physics engine is quite accurate and… well… forgives less than some game engines do