lesson7.txt

#color 0xffc3e1fe
#coord 305 17
#title The Subframe Lessons
#title 107: Particle Visibility

#font 7px
#color 0xfffbfbbb
#coord 37 46
#section 7.1 Particle Visibility

When particles are stacked, you can only see the topmost particle.
Similarly, DRAY can only "see" the topmost particle in a particle stack.

For example, this setup attempts to copy an INSL stacked over a CRMC.

If you SPRK the PSCN, the DRAY duplicates the INSL.
However, the CRMC is not duplicated. Use box delete to verify this.

Since the CRMC is not the topmost particle in the stack,
DRAY cannot "see" it and thus will not copy it.

#section 7.2 Visibility Subtleties

Recall from Lesson 3 how ARAY is activated.

SPRK does not look for ARAY to activate; instead, ARAY looks for SPRKs.

This means that we can stack things on top of ARAY without disabling it.
It will update even if other particles can't "see" it.

On the other hand, we can't stack things on top of the PSCN:

- BTRY won't be able to "see" it and thus will not SPRK it.
- ARAY won't be able to "see" it and thus will not be activated by it.

The same applies to DRAY.

#font 5px
#color 0xffbefcc4
#coord 410 48
#section Activity #7.1

Use stacking to make this permanent BRAY
more compact.

#space 15

#answer 150 10

#section Activity #7.2

When making compact subframe electronics,
BTRY can get unwieldy due to its
large area of effect.

CONV(SPRK) is a special type of CONV.
It works just like BTRY, except that
it only SPRKs conductors that it touches.

You can make it by setting CONV's ctype
to SPRK. There is no need to set its tmp.

Try replacing the BTRY in the previous
activity with CONV(SPRK).

#answer 150 10

Bonus: Another interesting feature of
CONV(SPRK) is that it can SPRK a conductor
stacked directly on top of it.

#space 10

          BTRY            CONV(SPRK)