How to Master Match Perspective

[Robb63]

I've checked the KS manual, and other than it saying there is camera matching in Pro it doesn't really tell you how to work with it. I feel like I'm just dragging the XYZ arrows all over the place with no real plan on how to position them.
I've looked at quick-tips, and mini tutorials, but haven't seen anything there either.

Can someone walk through the best way to line up the XYZ arrows to get a decent result?

[Speedster]

First be sure to show the coordinate legend so you can then relate the three line/arrow colors and callout to the actual X-Y-Z.  Keyboard shortcut for the legend is the Z key, or View>Show Coordinate Legend.

Work with only one axis at a time, dragging the arrows to align with something in your backplate, like along a fence, landscape, tree line, road edges, etc., spaced as far apart as possible both left-right and toward the top and bottom (when in the Z axis).  The arrow heads are the drag points.  I usually work Z-X-Y, in that order.

Note that your model won't be showing, but don't worry!

When all three are correct, then you are free to move your model (camera) around to suit, and all will be in alignment.

Play with it a bit and it becomes quite easy, and a godsend for proper alignment.  Hope this helps!

Bill G

[theAVator]

Bringing this one back...

Are there any pointers/tips for when you have a backplate you're trying to match and don't have any reference details to work from? For instance, a desert scene or something in the woods, etc?

I saw the Newsletter tutorial from Aug., but that really covered more on the Lens Shift and less on Matching Perspective. A video tutorial would be great for matching in different scenarios.

[guest84672]

KeyShot Pro offers "Perspective Matching" which allows you to dial in the perspective interactively to match any kind of backplate.

[MisterNeil]

Hello,

I found this 2015 discussion on, "How To Use KeyShot Perspective Matching". Hope this helps.

Link:
https://www.keyshot.com/2015/how-to-use-keyshot-perspective-matching/

Neil

[theAVator]

Yes, that helps, but only if you're putting a truck next to a building that gives you verticals, horizontals and perspective lines to work with. However, not all work happens in a pre-cubed environment.

My post was really looking for how to use the Perspective matching, or just in general good rules of thumb for matching environments like those attached below, where all you might get is a vague horizon, and that's about it.

[TpwUK]

The only two ways I know of are (1) to eyeball things as best as you can, or (2) Wherever possible contact the photographer of the image to be used as a backplate and see if he has the data from the shoot. Camera height, lens size, f-stop etc then use the data for your camera settings. There are a few HDRI/Backplate providers that provide the camera shot details, but they do seem to be few and far between, so the rule of thumb would be to ask before you buy.

Martin

[Will Gibbons]

Best bet here is buy Scott Robertson's book 'How to Draw' and read the part on perspective until you understand it fully. Additionally, you should only be using your own photography as backplates... unless the photographer has made it clear that anyone can use the image for free. The perk to shooting your own backplates is that you have full control over the camera and you can access all the settings to match it. Finally, I recently learned from Richard Funnell, that some industry pros will shoot two backplates at once (with same camera settings). One will have a standard prop (say a 1x1x1m white/gray cube). The dimensions can be whatever you find it easy to work with. You probably can find a collapsible wire/fabric one of these online for cheap that's easy to travel with. Start by using the perspective matching tools in KeyShot to match the plate with the prop, then swap it out with the plate with no prop.

That's an ideal, but very attainable workflow for pretty much anyone. Hope that helps/gives you some ideas.

[Speedster]

I have a big open-sided box modeled in CAD, with a widely spaced "grid" on each side.  I then drop this box into the model CAD assembly and mate it to suite along whatever axis, to use as a large scale rectangular guide to just visually align the model to the backplate.  Then hide it.  Works well if you trust your eyes!
Bill G