Projection mapping within AE

[Veronika Yurchenko]

Hi all, I have been trying to make 2D picture look 3D by projection mapping within AE from this tutorial- https://youtu.be/ldfYFsDUspU. It wourks perfectly if the picture was taken with all angles equal and vanishing point is in the middle. However I'm now trying to work on a photograph that was taken slightly from a side so the vanishing point is off centre and also the two lines on either side run at different angles. It becomes tricky to rotate the layers to match the source. Basically the question is is there a way to build this 3D box and then have it positioned at the right angle before I project my image onto it? I'm hardly getting my head around doing it with a straight forward image, so struggling to understand whether I can do it with another image with an uneven angle. Any help at all would be so appreciated 

[Roland Kahlenberg]

Look at Set Extension techniques to create a more workable image.

[Rick Gerard]

This kind of stuff is easiest to do if you use the Vanishing Point effect in Photoshop and export a VPE file. It's pretty hard to find a really good tutorial on this technique, and it takes a bit of time to figure out how the Vanishing Point tools work in Photoshop. 

You can do all of that kind of stuff directly inside After Effects and the camera angle doesn't really matter. You just have to start figuring out where the planes are and you do that by adding a grid and then rotating and positioning the layers until the grid starts to line up with the perspective in the shot. It helps to know something about the focal length of the camera used to take the image. You can sometimes find that in the Meta-data. Match the focal length of the camera (50mm AE camera for 50mm lens on a full-frame DSLR) and then start positioning layers in AE's 3D space and you'll get it figured out. The advantage of using Photoshop is that it distorts the image slices and creates layers for you. 

Let me know how much experience you have in AE's 3D space and show us the image you are trying to use and we can be of more help.

[Veronika Yurchenko]

Thanks for your reply. I've looked at Vanishing Point effect in Photoshop but apparently it didn't work so well and so in thelatest version the option to export it as a VPE file has been dicontinued.

Will look at the meta data but im quite sure my lens was at 24mm when i shot the image and im setting this for the camera inside the AE, but still not able to align the planks to match the angle.

I have a bit of experience within AE's 3D and understand the basics of changing orientation of a layer.

Here's the image i've been working on.

[Rick Gerard · Accepted solution]

VPE is alive and well. I have the last 3 versions of Photoshop and AE installed and the option is right there in PS and you can import them into AE.

That image looks like one from a tutorial. I don't see a link to the tutorial it came from or any real description of what part of the process is giving you problems. VPE would work but so would Projection Mapping. You won't be able to move the camera very far to the left or right and the arches are going to distort quite a bit.

I don't have time to go through the most efficient way to set up a comp for projection mapping, but that image should present no real problems. This is less than 5 minutes work and it involves setting the anchor point of the solids at the right edge of the layer, rotating 90º and positioning the layers on the edges of the frame to create a box, then creating a camera null and adjusting the rotation of the null to point the camera in the right direction, then adjusting the z position of the camera to get the right perspective, then adjusting the Zoom value (focal length, to frame things up properly. I don't recall any tutorial that explains how the camera position determines perspective and the focal length controls the framing. Just dropping 3D layers in a scene and trying to line them up by dragging the layers around is a very inefficient way to set up the 3D world. Anyway, maybe this screenshot will give you some ideas.

[Veronika Yurchenko]

Thank you for such in-depth reply. Somehow my Export for AE (vpe) option is greyed out in Photoshop. Sorry to sound like an idiot, i'm just a beginner at this and so didn't know i had to make a camera null to find the right angle. Also moving the anchor point definitely should have helped too! In the end i did it a completely weird way, first switching to a different focal length (15mm) and then extending the composition to move the image so the vanishing point was in the centre. I know, completely stupid, but i did it before your reply. It worked in the end but thanks for explaining I needed a null camera. Will definitely be doing this the right way next time.

I guess my understanding of 3D is still work in progress...

Thank you again, i really appreciate your time and effort!

[davids29636651]

Unless I a missing something the import vanishing point .vpe in AE never lines up with the orginal plate making it unusable for VFX work