Altium 21 snap grid issue - Page 1
Forum section: electronics / general

author: hansibull
author_rank: Regular Contributor
timestamp: March 17, 2021, 11:04:48 am
content: Hi!I'm currently using the latest Altium 21 version, but I've had this issue for many months.The problem is the snap grid when moving parts or placing vias. Even though I set the snap grid to 5mil, it still randomly jump around, usually in 10mil steps.As you can see in the GIF, I'm not able to place the via on the slightly thicker white line, without holding down the CTRL key (which is not what I want).Does anybody know how to fix this so that everything can snap everywhere on the grid?EDIT: it doesn't seem like this is an issue if no tracks are attached to the via. In the GIF below there is a trach attached, but the layer is not currently "in focus" (using shift + S).

author: E-Design
author_rank: Regular Contributor
timestamp: March 17, 2021, 11:31:58 am
content: Could it be due to a design rule for tracks to adjacent / different signals? If you turn off design rule checking does it behave differently?

author: voltsandjolts
author_rank: Unknown
timestamp: March 17, 2021, 11:41:44 am
content: Likely something to do with snaps or design rules, not sure.In a lot of your posts (including this one) you are linking to images on external sites.Could you please not do that and instead embed them here on the forum, because over time links go dead and leave a mess in their wake.Thank you.

author: hansibull
author_rank: Regular Contributor
timestamp: March 17, 2021, 12:11:51 pm
content: QuoteThanks, but how do I disable the design rules and/or DRC? I've never done this before because it's a silly thing to do when you're not fighting Altium.QuoteI first tried to upload the GIF directly here, but it was turned into a non-moving image, That's why I used Imgur.And to my/Imgur's defense, I have yet to see them removing or changing URLs. I have some Imgur images on my Github that's been there for seven years now. Still there!But I do agree that images related to the topic belonghere.

author: voltsandjolts
author_rank: Unknown
timestamp: March 17, 2021, 12:30:44 pm
content: Even if the GIF didn't play on page load, it would likely have worked for people who were interested enough to click the download link and view it.Don't trust any image hosting sites, look at the unholy mess Photobucket made when they decided it was time to cash-in.https://en.wikipedia.org/wiki/PhotobucketRules/DRC:Rules edtor has 'enabled' columnAlso see Tools > Preferences > PCB Editor

author: RiZsho
author_rank: Contributor
timestamp: March 17, 2021, 06:01:48 pm
content: Hi!Have you tried turning snapping off? (toggle it with Shift+E)

author: ajb
author_rank: Super Contributor
timestamp: March 17, 2021, 06:43:26 pm
content: Altium just has really shitty snap behavior. The only way I've found to get it to stop fighting me like this is to turn off snapping entirely, which is effectively what holding the Ctrl key does. You can also turn off hotspot snapping like RiZsho mentioned using Shift+E (which actually cycles through three different modes). There are a bunch of options in the snap section of the PCB properties panel (when you have no objects selected). The conflict resolution mode also matters, you can cycle through the options using Shift+R, and setting it to Ignore Obstacles will give you complete freedom to put the things wherever you want--and of course create DRC violations in the process. Reducing the snap distance also helps, this requires you to get closer to a snap point before snapping to it, but this of course makes it harder to snap to the things you WANT to snap to.In a previous job I did a lot of AutoCAD work, and I desperately wish someone at Altium would take a look at their snap system, which is truly the best I've seen in any software ever. Great granularity in what you can snap to, which angles snaps are tracked in, and the snap tracking is extremely well done, which makes it very easy to line objects up based on snap points without having to dodge a bunch of snap points you don't want. You can even create temporary snap tracking points on-the-fly in the middle of other commands, so for example you can track off the ends of two non-intersecting line segments to extend them to where they would intersect, then create a temporary track point at that location, and then track off of that temporary point in whatever directions you've configured.But mostly I just want Altium's snap system to not be an active hindrance like it is now.

author: hansibull
author_rank: Regular Contributor
timestamp: March 17, 2021, 09:39:34 pm
content: I think I figured it out! When nothing is selected, open the properties sidebar/window/whatever. Here there were some additional snap grid settings that can't be found anywhere else. "Snap distance" was set to 8 mil for some reason, so changing it to 5 mil solved my issue.BTW is there a way to set an actual grid when holding down the CTRL key, for instance, 0.5 mil or 0.05mm? At the moment it's just my mouse and/or my screen resolution that determines the accuracy. I'm getting mil coordinates with three decimals. Ridiculous...EDIT: I figured this out earlier today. If not ajb's answer would have gotten me on the right track. Thanks, everybody!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 17, 2021, 09:58:47 pm
content: FYI, I find it useful to tap the arrow keys for precise positioning. Partly a habit built from older versions (that seemed to have the same behavior, which I didn't think was due to grid size, but now I need to check, hmm..!), partly because, well, it's accurate grid steps and counting. Also SHIFT+arrows for ten grid spaces.Downside, sometimes arrow-key positioning plays weird. Especially in SCH. I think it's trying to move the mouse cursor to the predicted next location, and for a variety of reasons (ancient mouse API? rounding errors?), sometimes it does two, or zero, or throws in a step in Y when you only moved +/-X, etc...Tim