I chose that picture (that @ijw is saying is wrong for a different reason) because it only works if the blast focus is bigger than a mathematical point. But it is called the same thing regardless of template type in the rules and LoF is drawn from it either way. I don't think pretending that those two blast foci are totally different is consistent either.
The problem here is that the teardrop when used as DTW is not well detailed. The DTW need the ability to rotate the template so you can aim to models in a diferent level than your model. It makes sense the focus is different in this case (or that you have more flexibility placing it) but the rulebook makes an awful job explaining that. Ok, I'll try other version it with that in mind. What does infinite height means regarding to smoke : 1) infinite height in both direction (upward and downward) 2) infinite height, but upward only What is the nature of the blast focus of a circular impact template: 1) A point in the targeted surface with unknow dimensions. 2) A point infinitesimally above of the targeted surface with unknow dimensions. 3) A point in the targeted surface, which correspond with the center of the template placed; the blast focus have no dimension (including no height) 4) A point in a point infinitesimally above of the targeted surface, which correspond with the center of the template; the blast focus have no dimension (including no height) Are the played allowed to select the target 3x3mm zone just right next to a border? 1)No, the targeted point must be the center of that 3x3mm zone, if you choose a point too close to the border that attack would be illegal and cancelled. Hence, there is no way to place the 3x3mm zone perfectly just in next to a border without allowing perfect intent (Perfect intent is not supported by the rules confirmed by ijw in this same thread) 2) Yes, you can place the 3x3mm zone around the targeted point as you wish. Hence, you are allowed to place that 3x3mm zone just in the border. Can the Blast Focus be placed at the border of a roof/wall? 1) No, because you cannot place the 3x3mm zone just in the border (see question above). 2) No, you need to see at least a 3mm square of roof. Blast focus will be in the middle of this square. 3) Yes, nothing forbids you to place your blast focus on the border of a wall/roof. 4) Yes, you can place it on the border of a wall/roof but you will need to use speculative fire to being allowed place the blast focus off-centered. If the blast focus can be placed just in the border of a roof/wall (see question above), can LoF be traced downwards from that point? 1) No, you can't place the blast focus in a border, see above. 2) No, even when placed in the border the LoF is only supossed to be unpwards, never downwards. 3) No, even when placed in a border you need to trace LoF to the center of it so you cannot trace LoF downwards (assuming it have volumen) 3) No, even when placed in a border you cannot trace LoF downwards for other reasons (in this case is true, please add reasons). 4) Yes, a point just in a corner would allow you to trace LoF downwards. Bonus question: What is the nature of the blast focus of a teardrop template: 1) A point with no dimensions at the narrow end of the teardrop template. 2) A big circle at the narrow end of the teardrop template whose perimeter coincide with the narrow end of the teardrop template (around 180ยบ) 3) A point with no dimensions at the narrow end of the teardrop template; however you are allowed to place the teardrop template as it were as big as described above.
@BLOODGOD I see regardless of the picture been wrong, the picture is illustrating different ways a shotgun template can be placed to get more targets. From memory and in contrast to direct templates I think is is assumed the circular area of affect template is placed at the targets base (or the lowers vertical surface in case of smoke or speculative fire) and not at a potential airburst.
Ah, OK. We have always played it that way, narrow end of the Teardrop touching the edge of the base I mean.
Ok, final proposition for the unanswered questions : What does infinite height means regarding to smoke : 1) infinite height in both direction (upward and downward) 2) infinite height, but upward only The following question applies both to targetless circular template (smoke...) or speculative fire What is the nature of the blast focus of an impact template (question for both circular and teardrop template, answer can be the same for both, or not): 1) A point in the targeted surface with unknow dimensions. 2) A point infinitesimally above of the targeted surface with unknow dimensions. 3) A point in the targeted surface, which correspond with the center of the template placed; the blast focus have no dimension (including no height) 4) A point in a point infinitesimally above of the targeted surface, which correspond with the center of the template; the blast focus have no dimension (including no height) 5) A circle of unknown dimension (as shown in the teardrop template pictures) Answer 1 to 4 : the blast focus is a point : Are the played allowed to select the target 3x3mm zone just right next to a border? 1)No, the targeted point must be the center of that 3x3mm zone, if you choose a point too close to the border that attack would be illegal and cancelled. Hence, there is no way to place the 3x3mm zone perfectly just in next to a border without allowing perfect intent (Perfect intent is not supported by the rules confirmed by ijw in this same thread) 2) Yes, you can place the 3x3mm zone around the targeted point as you wish. Hence, you are allowed to place that 3x3mm zone just in the border. Can the Blast Focus be placed at the border of a roof/wall? 1) No, because you cannot place the 3x3mm zone just in the border (see question above). 2) No, you need to see at least a 3mm square of roof. Blast focus will be in the middle of this square. 3) Yes, nothing forbids you to place your blast focus on the border of a wall/roof. 4) Yes, you can place it on the border of a wall/roof but you will need to use speculative fire to being allowed place the blast focus off-centered. Can the blast focus be placed just in the border of a roof/wall (see question above), can LoF be traced downwards from that point? 1) No, you can't place the blast focus in a border, see above. 2) No, even when placed in the border the LoF is only supossed to be unpwards, never downwards. 3) No, even when placed in a border you need to trace LoF to the center of it so you cannot trace LoF downwards (assuming it have volumen) 3) No, even when placed in a border you cannot trace LoF downwards for other reasons (in this case is true, please add reasons). 4) Yes, a point just in a corner would allow you to trace LoF downwards. Answer 5 : the blast focus is a circle Can the blast focus be placed at the border of a roof/wall so LoF can be traced downward from the blast focus ? 1) Yes. You can place it on the border and LoF can be traced to any point of the blast focus so you can trace LoF downward 2) No. You can place it on the border but LoF can be traced to only to the center of the blast focus so you can't trace LoF downward => Added to the unsolved question list
If you stack paper on a desk, let's say you stack it very high, let's imagine you stack it even higher, and higher, and higher, and infinitely high. Why would you think there will ever be paper going on the floor below the desk ? The stack will never reach a limit forcing you to extend the stack in the other direction.