1) 3D Boxes don't manage collisions. This is annoying, you have to create colliders for everything! There are 2 problems : neither starting the condition from a 3D box nor from the object that must collide with it works :
When sprite collides with 3dbox = events (nothing happens)
And, you can't even manage collisions in 3Dbox.
2) Depth too high by default. The "1" depth we have now should be 5, since we can't use decimal numbers.
I'm really begging you to add collision support
I've been working with the 3D Box quite extensively and I'm afraid I can't recreate any of the problems that you're having.
I made a test .cap to see if I could test for collision between a sprite and a 3D Box. I gave the sprite 8-Dir movement, and added this event (just as you described:
Condition: On collision between Sprite and 3D Box:
Action: Sprite2: Set X to Sprite2.X+10
Every time I collide Sprite with 3D Box, Sprite2 moves ten pixels to the right. Here's the test .cap to see for yourself:
This is with the 3D Box's "Solid" attribute turned off.
Now if you turn on Solid, then I can recreate it. Your sprite and the box won't be able to overlap and register a collision, at least with the default movements. It seems like Construct is checking objects against their Solid attribute before checking the event list, so objects with Solid turned on will be pushed apart before the collision condition occurs.
As for the Depth, I'm really confused. I can enter in decimal values just fine:
The Depth and Z values for these boxes were entered into the 3D Box Properties without any problem.
As for collisions with the 3D Box, you have to keep in mind that the box is just a rendered overlay on top of a 2-dimensional bounding box:
The collisions between the box and other objects occur at the bounding box, regardless of it's Z depth. This means that even if it appears "above" or "below" your sprite, it will still collide at the bounding box.
As Ashley said, the "bounding box" is actually a mask of the back face, but the idea is still the same. It's a 2D area that stays on the same Z plane as your sprites.
As for your back face rendering: The faces are one sided. This is the default with just about every 3D program. The faces won't render unless they are facing toward the display. Try changing the yaw of your box to rotate the back face forward and you will see it.
I've been meaning to ask if Ashley would put a "Render 2 Sided" option in the textures panel, but he's busy with other stuff right now and I've already asked for a crapload of features for this object