UV Mapper - Frontal Projection

I'm needing to map a 2d landscape image (field) onto a plane that represents the field so that I can then place objects on the field and they will cast a shadow onto the field. My camera is 'close enough' to the real image's camera position. I've done this before using the UV mapper tool and projecting the image using Frontal mode. Today I can not make it work at all (image is distorted and angled etc.). Tomorrow I'll make some screen grabs and post a file... unless in the meantime someone can confirm for me that its not working as it should ??

Any insights will be appreciated - thanks in advance!
--shift studio.
 
Plane is 1:1:1 in scale and has same aspect ratio as image?
And i´m not sure why you need the UV-mapper at all when plane + image have the same proportions; the default UVs should do - no?
And UV-mapper works as expected here BTW.

Cheers
Frank
 
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Hi Frank.
Glad to hear it works. Yes plane is in 1:1:1 scale, but it does not have same aspect ratio. The reason I was doing it this way is because I was going to 'cut off' the sky that is in the image while projecting, and also the plane extends behind camera. But thats not the only problem I had, and I think I've figured out where I went wrong... I thought of it when I woke up this morning. The plane is only a single polygon, and the way I had it set up part of the single polygon would have no texture mapped to it - and thats not gonna give results I need.
I may continue down this road with the UV mapper, or I may crop the image externally and do as you suggest (default UVs).
I'll report back.
Thanks Frank.
--Shift Studio.
 
An update - Frontal projection works as expected. If you have your image set to NOT tile, you need to make sure the image fills entire polygon(s) or the results are strange (can't describe it) ;)

--shift studio.
 
I find the easiest way to align an image with a plane/terrain/etc is to set the scale to something you can adopt from the image size like: 1234x867px = 12,34 Width x 8,67 Depth and all will be fine - no need to look up UVs or use of UV-mapper - just drag&drop. :giggle:

Cheers
Frank
 
I find the easiest way to align an image with a plane/terrain/etc is to set the scale to something you can adopt from the image size like: 1234x867px = 12,34 Width x 8,67 Depth and all will be fine - no need to look up UVs or use of UV-mapper - just drag&drop. :giggle:

Cheers
Frank

Thanks Frank.
I don't think you and I are talking about the same thing. I needed to place these CG 'evidence markers' in this field image (I can't provide the original field image here as it is a purchased stock image). I used a CGi horizontal plane with the same field image (UVmapped using frontal projection) to represent the field and catch the shadows and also provide some reflections into the markers.

I can't wrap my head around how you would do it just placing the image on the same-aspect-ratio plane. But if you did understand what I needed to do and I'm just being dull, can you indulge me with an example?

Here is what the image looked like when completed (sans blurred product name). The ad that this image will be used in is still in approval stages.
CGMarkersonFieldImage-.jpg


Thanks, Shift Studio.
 
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Well - I can´t explain it any better - just louder:
This is my image=1024x80px:
ProportionalImageTexture.png


This is the image loader and how I apply it to a plane of Width1,024xDepth0,08
LoadTexture.gif



If you need a tiling texture you can set Width to 3*1,024 - leave Depth at 0,08 and set UV Scale X= 3 (times)
Adjust iterations and Bend- or Wrap-modifier and you´re good to go:
CrimeSceneTape.jpg

If there´s still anything unclear let me know.

Cheers
Frank
 

Attachments

  • crime scene tape.zip
    21.9 KB · Views: 228
Hey Shift.
If I am picking up what you are laying down, you are using a single “quad” for your ground plane?

Try using the subdivision modifier on the CG ground plane. The more levels you throw at it, the less distorted the projection will be.

Example:
Straight Square Projection…
square.jpg
Skewed Projection using single quad…
Skew1.jpg
Skewed Projection using linear subdivision…
Skew2.jpg

If this is not the problem you are having, disregard post.
 
Hi Guys, I got the frontal projection working as it needed to be last week and the project is pretty much done I'd say. So we don't need to continue on - but it may be helpful to someone else in the future. In the end I rendered my image elements in a few different passes and composited in Photoshop. I never did render that plane with field image on it, it only served to contribute to the other elements (triangle shaped markers and ribbon).

@Daemoc Thanks for the reply and pics. Yes, I think you are picking up what I was laying down. I did subdivide and also skew my plane.
@frank beckmann Thanks for your help as always - the image, animated gifs and files are especially helpful! This time I guess I didn't explain myself clearly enough to convey what I was doing. Its a good technique that you've illustrated above - one that I've used many times myself. Hopefully others will get some help from the work you did on this for me.

Here are two screengrabs that may illustrate what I did to make the scene>>
CGMarkersonFieldImageCamera.jpg

CGMarkersonFieldImagePerspective.jpg


thanks again!
--shift studio.
 
It seems I totally misunderstand what you´re after and in addition mixed "flat" with "frontal" projection.
I don´t understand why it´s needed here though.

Cheers
Frank
 
It seems I totally misunderstand what you´re after and in addition mixed "flat" with "frontal" projection.
I don´t understand why it´s needed here though.

Cheers
Frank
'Frontal' is a bit of a weird name for this kind of projection to me.
I didn't even really use the plane as I originally intended. At first I was going to render the field(plane), markers and crime scene tape all in one, using Falcon renderer, and the plane would catch the shadows. But later I decided I could tweak it better if I composited the elements in a raster image editor (Photoshop).

Again, thanks for the help.
--Shift Studio.
 
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