Ever notice when you try and flip a automobile for a reflection on a showroom floor it doesn't look right?


This has been posted here before but with no results that looked correct.
I am re-posting to see if anyone has new developments to achieve this effect.

It's not easy in Photo Shop CS5 either.Although i can get close with skew. Puppet Warp doesn't work.



Can anyone achieve this?
You can use my image here. It is mine so you can do whatever you like with it.

wbool63 made a pretty good stab at it way back...looked good to me. I don't remember where the thread is though.

Found it here Molly. Thanks.
http://www.gimpchat.com/viewtopic.php?f=8&t=3235

Seems like we could do better though.

This is a hard challenge, this is my thoughts so far, I have created a path to reflect the perspective of the initial image and duplicted this path to reflect the perspective of the reflection so both are Identical, now if I could map using the path of the reflected image onto the path of the main image might have something usable.

I was getting bored with the whole process but here is what I have managed to achieve, cropping the image into slices of 10px thick and then offsetting the reflection layer in a negative y direction by the difference between the two paths, ideally it would be better if you could do slices only 1px thick, hence this method really needs a script. but as mentioned in the other thread technically the reflection would still be wrong because it wouldn't be the complete reverse of the car being able to see the underneath etc.

This is the thread I was referring too where Wbool actually used a graph to show what it would look like.

viewtopic.php?p=41707#p41707

This nev er works because the reflection must include details (the underside of the car) that aren't in the original image. A reflection of a 3D object is not just a symmetry. It's a different point of view.

This is what I've been trying to duplicate (without success to this point):

Is this what you're after, or something else?

This.

Yes Mike this is the effect i want but without the underside of the car reflected. I suppose the best way is to have the image of the car as horizontal as possible.

If you don't want the underside reflected then you must chose another car image to work with.
with that you have , in that position, the prospective and the reflection will always look wrong without the underside.

you may do without only when the point of view and prospective only require to mirror what visible for a realistic reflection that is a rare case

And there are also parts that you don't see in a reflection (like most nearly horizontal surfaces....). Look at the picture posted by Mike. In the reflection there is no hood, no windscreen, no roof, no air intakes...

Yes it's even very difficult with a nice horizontal image.

"Very difficult" seems a euphemism here
I believe is just impossible do "automatically", there are part in the reflection that can't be derived from the original 2D image or even from a single 3D render.

They may be invented that require creativity and a good manual work ,
but my point is that the manual work needed can't be generalised, the procedure will differ from image to image:
what will work for that car in that position can't be adapted to a different car or even to the same car if seen from a different different POW or FOW

As a quick way to do this without manually slicing, you can distort the image using a constructed gradient. Draw a path between the two shapes, crop that to a rectangle, shrink that layer to a 1px high layer (with linear interpolation), then enlarge it (with no interpolation) to the image size and use that as a displacement map:


Still looks completely wrong as a reflection, but could be used for other things, or if the source image is not so skewed, or is only in one point perspective.

-Rob A>

Great idea Rob.
Thanks!

This is a tough challenge due to the type of car and not having the underside details of the image. I think it might be easier with a more modern car with a lower stance, but I've come across this issue before when attempting to create reflections of other things as well. With other objects, I've been able to make the reflection match up with the original image, but something always looks odd about the reflection not having any of the underside details.
On close inspection, one can tell that it's just a manipulation of the original and not a true reflection. Due to the missing details.