Rigid Body and Material / Table Collider and Trigger

[finnfirrior]

Hello, I just wanted to confirm.
Since my English not too good so I need some help.

Kinematic: the bouncing will direct some position we target
Dynamic: Normal Physics
Static: no Physics implement
Is this right?

On the table, we saw Collider and trigger event.
If object a has a trigger and object b no trigger then the event still triggered and no collision happen.
Is this right?

I found we can put material in a rigid body, why put it in a collision?

[Nina]

Hi Benny,

Thank you for your questions.

#1: You are right.
#2: If the game object has no collider attached, no collision event can be triggered by this game object.
#3: The Rigidbody on a parent game object acts as a compound collider. It collects the collision information from the colliders on the child game objects. If you attach a material to the rigidbody, the colliders on the children get this material attached unless they have their own material.

Did this clear it up for you?

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[finnfirrior]

@Nina

#3: The Rigidbody on a parent game object acts as a compound collider. It collects the collision information from the colliders on the child game objects. If you attach a material to the rigidbody, the colliders on the children get this material attached unless they have their own material.

clarify about this one if i put the material on rigid body, so the child will be have material too?
but if put on colider the chlid game object wont have the material?

btw i kinda forget something.
when i move paddle or ball the position of x n y is 16:12 (4:3)

I understand when on bg i use 1440x1080 and 90 pixel/unit.
but why on ball or paddle the pos x n y still 16:12

[Nina]

@finnfirrior

clarify about this one if i put the material on rigid body, so the child will be have material too?

The Colliders on the child get the material from the Rigidbody unless the Collider on the child already has got a material assigned.

I understand when on bg i use 1440x1080 and 90 pixel/unit.
but why on ball or paddle the pos x n y still 16:12

You’ll have to do the maths to figure out what’s going on here. Rick calculated his values for a 4:3 aspect ratio and a resolution of 800 x 600 respectively. Your values have to be the same as his to get the same result as he without changing anything.

[finnfirrior]

What kind math solution i need use?

resolution i use is 1440x1080.
but in BG i use 90 ppi(pixel per unit.)
i understand my transform is end up 16:12.

but my paddle ppi is 120, the maksimal pos X on this case is 16.
didnt it should be 12:9?

[Nina]

The following thread might help.

Camera Size and Aspect Ratio

I have a question about the unit size when you set it on inspector. If you have a aspect ratio 4:3 then the total height in units would be 6 and the width 8 right? So if I set the size to 6 (half of the height) the total would be 12 and the width, logically would be 14 units. So why on the video he told it is 8 (total: 16 units)? It may be a silly question, but I really didn’t get it! Thanks!

You’ll have to decide what size in World Units (WU) the paddle is supposed to have. The pixel size is irrelevant in the scene. If your paddle is supposed to be 2 WU wide and its width in pixel is 122, you set the Pixels Per Unit (PPU) value in the Import Settings of the sprite to (122 / 2 = 61).

[finnfirrior]

i still didnt get the idea.

where i can edit the WU?
if we doing the math correctly the WU supposed 90PPI?

[Nina]

You cannot edit the World Units. They just exist like all the other units such as metre, kilogram and so on. The PPU can be edited. Click on your sprite in the Assets folder. Then you should see the Import Settings in the Inspector. There is a property labelled Pixels Per Unit.