Perspective matching need a hint to proceed

[keith_brown]

I've watched dozen of videos and all having examples with super clear buildings or streets where there're a lot of reference points to use.

But here, I'm lost. Where should all the lines travel?

[RobH2]

For that kind of image you have to sort of cross your fingers and find what you can. Most of what you have chosen looks OK but the two lines that you picked on the road don't look like they are parallel in the real world. I'd play with those a bit. 

Edit: One thing to be aware of, if you go back to that site, that same car and road are in several different backgrounds already. So, it's a composite and not from a real world photo. That means, you can't trust the perspective and vanishing points to be real or correct. It's unlikely you'll ever get a perfect camera match regardless but by playing with it, you can certainly get something "good enough" for what you need. 

When there are no clear perpendicular lines in the scene, you have to get creative and be the artist. Just keep aligning it until it's close enough to looking good in whatever you do next with it. You'll likely have to do it or fuss with it a few times. 

Edit: Something to be aware of. If you go back to that site you'll see that same car and road in several backgrounds. So it's already a composite. That means you can't trust that it has proper or real vanishing points. Meaning, you'll likely never get a perfect real world camera solve from it. But, you can push and shove on it and get something good enough for what you need most likely. 

[keith_brown]

That's a good point you got there with the composite! I give up. Been struggling around for too many hours with this now. Eye balling kind of generated a better result. But still, I'm trying to conquer a big task. Not only perspective match one viewport but two that aligns correctly around one object.

I challenged myself to model a car with a different approach compared to using the traditional blueprint. Overwhelming task I realize. Working with the Perspective Match tool in combination with tweaking different camera tools (walkthrough, dolly camera and field-of-view) turned out to be quite wonky some times.

Why can't the Orbit of interest be used in camera mode like it can in perspective mode? Everything is just so much easier to navigate/rotate i.e. in perspective mode. My favorite one, ALT+Middle mouse button is a breeze. But as soon as a camera is applied it's a complete different behavior (panning). 

[RobH2]

If I can help you further I'm glad to. I do a lot of these but nothing too fancy. I don't do any camera moves as mine are all static cameras to match up with architectural photos into which elements are dropped. 

If you need to do moving camera work, you need to use some Matchmoving software. Syntheyes is reasonable, powerful, very difficult to use (just my opinion) and has outstanding support. Boujou was around for a long time and was really expensive. There are others if you Google it. 

Perspective Match is not the right thing for you if your camera is moving. Unless I'm underusing it, it's really just meant to match a still image so you can drop a new object into it. 

If you need really good Matchmoving, have a look at Davinci Resolve Pro. It's not too expensive and it's very, very good. I've tried several other Matchmoving programs but I find the learning curve on them really tough. I can more easily wrap my head around Davinci Resolve Pro, plus, it's an outstanding NLE video editor and has almost replaced After Effects for me.  

[keith_brown]

Thanks for the response! I updated my previous post a bit. But there will be no motion involved where cameras are moving. Just still images like you mentioned.

[RobH2]

I'm impressed you are doing a car. It is a lot to bite off. I find Perspective Match easy and good. You have to do it correctly. You have to start in a Perspective viewport, not in a Camera view. Your goal is to make a camera, not to force a camera to a desired perspective. 

[leeminardi]

Try using where the tires meet the road.  For example,

[keith_brown]

@RobH2 

Yes, that's how I do it. First in the perspective mode. Then adding a camera (tried both corona cam and 3ds max cam). Annoying though, sometimes all the lines I've matched jumps slightly of so adjustments yet again has to be done 😐 In the end I've fiddling around with the dolly cam panning, walkthrough i.e.  This means the vanishing lines has moved again (which I understand by nature is an expected behavior).

[RobH2]

Ok, glad you are starting in a Perspective viewport. I've helped a lot of people starting in a Camera viewport and having terrible experiences. Once they started in Perspective, they had good result. 

Something that helps me is that I always turn on 'Allow Distorted View'. It seems to help alot with some where I don't have good references to align to, like in your situation. 

Lee's tip is good as well. Use those tire's contact points and try to visualize where that obscured rear tire touches for the final line's angle. 

[keith_brown]

Tried your suggestion and added a dummy box to see how the edges travel along the box. Still don't sit quite right:

[keith_brown]

Is there a way to reset the vanishing lines and skewed angles?

Right now I delete the camera, then in the perspective viewport clicking this icon:

[RobH2]

I don't know if you have or havent, but if you haven't studied 'Vanishing Points" in school it can be confusing but it's what Perspective Match is trying to simulate to create a proper camera. Sometimes if I have a photo with few or bad vanishing references, I'll open it in Photoshop and actually just try to draw what I think is the vanishing point and vanishing lines using its perspective tools. Then I save that and open it as the Perspective Match background in Max, make my camera and than swap in the good background photo. 

But for that to work, you need to know a little bit about 'Vanishing Points' and if you don't, maybe a few Google tutorials are needed. It will help you wrap your head around where the lines are supposed to go. Most importantly, the lines you choose in Max to put the red, green and blue lines over, need to be ones you know are parallel to each other in reality. I think you already know what but just wanted to say it. 

[RobH2]

FYI, that screenshot of the button you mention is too small to know what it is. Can you provide a larger one?

[keith_brown]

Hehe, it's quite small in general. I didn't see what it depicted before I zoomed in on it 😛

In perspective mode, clicking that house icon resets the grid/angle position, but everything remain skewed if one has been playing around with the field-of-view tool. 

A solution to this I read was to create a camera, set the default field-of-view value on the camera and switch back to the perspective mode. Then it will inherit the values. Should at least exist some sort of input to enter field-of-view values straight for the perspective view? Not really a preferred way having to add and remove cameras just to reset the field-of-view so to speak.

[RobH2]

The vanishing points (VP) and horizon line (HL) are set too low if you use the car to construct them. If you don't know much about VPs or HLs, that could be part of the problem as it's critical to have a good basic understanding of perspective drawing when you start having to intervene and make manual decisions about it. 

Raising them will help. Now, vanishing points and horizon line are part of the Perspective Match tools, but you can, with some knowledge and thoughts about them, affect where they end up. It's sometimes helpful to print the image out and hand draw some lines on it to try to get it right. Or, do it in Photoshop. 

To me, it looks like the car is shot with a different hypothetical lens than the background. That will cause a disconnect visually. The car is kind of wide angle, like a 28 or 35mm lens or so. The background looks like a 50 or maybe 80mm lens. I think if the car used a longer lens, it might fit in better and look like it belongs there. 

[keith_brown]

Thank you for the response!

[RobH2]

One more thing I've found about 'Allow Distorted View'. I have a client who gives me a lot of architectural interiors and I have to Perspective Match to them. They are always pre-corrected the make the verticals perfectly parallel. I don't get the original files. Anytime a photo has "any" amount of perspective tweaking in Photoshop, it destroys the real-world perspective and vanishing point. 

When they do that, they destroy the real-wold perspective. There is no 'Vanishing Point' anymore so Perspective Match doesn't know what to do. Perspective Match expects real perspective and when it's not there, it's a problem. In this case, by turning ON 'Allow Distorted View', I can get a better solution. I think that's  what the switch is there for but haven't researched it. Anyway, it allows me to use these already corrected files without as much headache.