Altium: Can you disable the thing stopping you flying through the PCB in 3D view - Page 1
Forum section: electronics / general

author: Psi
author_rank: Super Contributor
timestamp: December 22, 2020, 09:12:09 am
content: In 3D view on Altium if you fly in too close to the PCB Altium seems to reduce the mouse sensitivity so you can't easily fly right through the PCB.I get why it does this but when using something like a 3D space mouse it's really annoying when Altium changes the mouse sensitivity dynamically.Anyone know if you can switch this off?

author: Elasia
author_rank: Frequent Contributor
timestamp: December 23, 2020, 03:21:23 pm
content: Quote from: Psi on December 22, 2020, 09:12:09 amThats weird? I dont think i've ever noticed that when using my trackman marble, if i want inside to see something i usually just max expand the layers then orbit in

author: Psi
author_rank: Super Contributor
timestamp: December 24, 2020, 12:11:51 pm
content: I think it treats the PCB as 0,0,0 in 3D space, and does 'moving towards the PCB' as a percentage change in distance.So the closer you get to the PCB the more your approach speed slows down.Or at least that's what it feels like.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 24, 2020, 02:37:36 pm
content: I think it's a little worse (hackier) than that, sometimes you can really crank on the scroll wheel (or hold PGUP/PGDN) and it sometimes judders about. I've even had it move slightly backwards (or to the wrong side when panning). Sometimes it manages to skip through the barrier (in which case you can't respond before you've moved the camera several meters away). Rounding error? Float precision? Something worse than that? Poorly calculated collision with some virtual board center?Also never liked that it puts the rotation blob (what's up with that* thing anyway, no one else uses a blob you have to click and drag onspecial points on its surfaceto change roll) at some fixed virtual distance, when you're not hovered over the board outline. So if you're trying to inspect some 3D models you've positioned off to the side, you... just can't navigate them, at all, you have to flounder around getting mere glimpses. The motion and rotation axes are inconsistent.*Rhetorical question, yes I know what's up with it, it's been there since the 3D mode was introduced (AD09, or was it in PCAD or whatever DXP was inbetween, too? I forget).Tim

author: PlainName
author_rank: Super Contributor
timestamp: December 24, 2020, 07:27:00 pm
content: QuoteOnce I figured out how to use it properly I like it. Well, at least compared to the solution other packages use (seemingly arbitrary rotations depending on, well, I can never figure that out).

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 25, 2020, 02:14:28 pm
content: 3D software I think has long used the principle that, what you're dragging, is the surface of a sphere centered on the origin (of the coordinate system, or the work, or of a fixed distance in front of the camera), that sphere being tangent to the view plane. So, left-right is a vertical-axis rotation (yaw), up-down is a horizontal axis rotation (pitch), and there's no way really to do a depth-wise rotation (roll) directly, which shouldn't be surprising with just two dimensions of control (a modifier key would do fine here, or assigning drag regions at the edge or corner, say; I forget if I've seen such methods, probably?).I've never used any that had the... just strange movement that Altium does. I have no idea what it's modeled after, if anything. I've never thought about it hard enough to figure out exactly what it is, mapping SHIFT coordinate and mouse coordinates to actual rotation. Like, for axis-aligned moves (relative to the SHIFT coordinate), it's like it's on a projected sphere, but as soon as you go off axis, it just flips around, all...weird. There's a locus of, if not a singularity, then very rapid rotation along some axis, whose angle is related to the line between clicks, or something.It's just so... bizarre. I recall everything from ancient Java applets to Solidworks getting it "right". Like, it's the default go-to rotation to do it like that [projected sphere], yet Altium went out of their way to do something else. Y'know?*In older versions. It was updated in, uh, AD18 or 20?. It's just different enough that I always second guess myself which way I want to move...Mind, I hardly claim to have made an exhaustive survey of 3D software. And there are other standard methods, I think which apply more in specific cases -- like game editors may prefer views typical in-game, e.g. first-person (rotation centered on the camera, and usually cylindrical i.e. left-right rotates around a fixed vertical axis, rotation not cumulative**).So, it's just one of the myriad oddities I've gotten used to (heh, and honestly one of the few I can remember and articulate, beside all the others that I don't even think about how weird they are anymore..) over the years using AD.(**Note that an X then Y rotation is different from Y then X, indeed this is the usual way to correct for roll when a direct control isn't available. Strictly speaking, it's completely controllable, there's no need for a third axis; but it may be convenient to provide one.)Tim

author: PlainName
author_rank: Super Contributor
timestamp: December 25, 2020, 07:24:13 pm
content: Do you drag the arrows on the ball? It wasn't until I dragged the actual circular bar and had it rotate perfectly controllably that I realised that's the primary mechanism and being able to drag anywhere in the view is just a nice to have secondary. At least, that's how it seems to me.