I have problem with this object's collider. Cannot find 3D collider for this floor. I cannot use 2D collider because my player is 3D player. When i put 2D collider, my player is falling. What should i do for it ?
I created half triangle and made it mesh collider. But it did not be succestful.
From the picture it looks like you're making a game with 2D perspective.
If you're making a 2D game it doesn't matter if the player uses a 3D model, it can still use 2D physics since you're not using the 3rd dimension.
My advice would be to change all the colliders to 2D colliders and use a Polygon Collider 2D component for the slope (triangle) object. This should adjust the collider shape to your sprite.