camera matching - improvement ideas

Started by andy.engelkemier, October 03, 2016, 08:11:35 AM

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andy.engelkemier

First and foremost, one thing that would Really help, is allowing us to overlay the backdrop image in Front with some degree of transparency. Alternatively, make the entire render a degree of transparency. That would be fine also.

Why? Because if you're matching only a product to a product, then your 3D product ends up blocking the product behind it. So it's pretty difficult to see. The perspective match tool will only get you so far.

Next, after that transparency option, which I Hope isn't too difficult, matching points.
I'm working on a project where I'm updating only a couple new pieces to existing photography and photoshopping them together in hopes no one ever knows. Some of the angles are fairly extreme, so that's not all that easy to figure out.
I'd like to be able to choose points on the image that have corresponding points on the model to calculate the camera position and angle. This option is in 3dsMax for sure, I'm pretty sure it's also an option in Blender, which also includes video tracking of those points.

When it may not be possible is if an image is cropped, or has lots of distortion. Does Keyshot let you render distorted images with wide angle shots yet? I was thinking no. But that would Definitely be nice, you could look at Vray for how they did that. I know you can do that there, but camera matching is pretty difficult. If the camera back was moved it also won't work, or if someone corner pinned the image.
But that should still get you a bit closer than just using perspective match...but not much.
But if the shot wasn't changed from the camera, and doesn't have much lens distortion, then it should match exactly. And the transparency option can help tweak the few pixels you might be off.

For now I'm using perspective match to Start my camera, then tweaking the heck out of it most times to get it nailed down. I'm looking at my shot list now and unfortunately 2 shots have a lot of lens distortion, so it's going to be pretty difficult. I may just have to experiment with removing the distortion, rendering to that image, then adding it back in.

guest84672

So "match perspective" in the environment tab doesn't give you what you need?

andy.engelkemier

The perspective match tools are great. But it could be a little easier to use.

If if you added a "loupe" view while selecting that pixel, then you could really get a bit more precision. I'm matching a handle that's coming almost straight at me. The horizontal is Very easy to pick. But the vertical is short, and the perspective that I see coming at the camera is Very foreshortened, so picking the perspective line and moving only 1 pixel greatly changes the camera. So adding some precision would help.
Also, many times the exiff data has much of the camera's information. Could start by reading that in?

The most valuable change to the tool though, would be an addition of a foreground image, with the ability to adjust it's transparency. Right now, your product blocks your view when trying to match shots. Making the object transparent is likely fairly difficult. Although I could be wildly incorrect, it seems adding a foreground image would be much more simple for you guys to do.
That would also give users the added ability of adding things to the foreground of their renders, if they choose not to do that in photoshop. Things like tree branches, or out of focus bushes or grass. A window looking into a room, a cheesy picture frame. Well, I wouldn't tell people what to do. I wouldn't render it with those myself, but it's nice to use them to preview it so you can more easily frame your shots if that's the end goal. And it would be a very useful tool for perspective matching.

guest84672

Thanks Andy. Good feedback and input. We are looking into adding front plates for 7.