#Replacing Carpet in Pic
16 messages in this thread
I have an interesting project. We have a photograph of a room full of
furniture. I need to be able to swap out the carpet in the room with various
carpet samples. This shouldn't be that difficult. Just use Photoshop or
whatever and cut out the carpet. Create a floor in 3D Studio that approximates
the angle of the floor and apply a texture map that is created with a photo of
the carpet. Render it and Video Post the furniture over the resulting picture.
The only problem is that I have to keep the shadows in the shot. I'm sure this
can probably be done somehow with alpha, but what would be the method? Should
you shoot the furniture "blue screen"? And somehow edit out the heaviest
blues? I'm not sure how to approach this. I suggested modeling the furniture
in 3DS but that was nixed.
Brent Bonet – POP! Multimedia Atlanta
Brent,
Just off the top of my head, it sounds like 3 images with video post might
work. One of the carpet, one of the furniture, and then a third image with only
the shadows. In that third image, set a level of tranparency or alpha in the
video post queue.
Anyway, just a thought…
-brian
I wonder how the shadows only image would be created? How do I manipulate the
alpha channel?
Brent Bonet – POP! Multimedia Atlanta
What I would do is take the photo with the shadows into a paint program
(Animator Studio or Photoshop) and just erase everything but the shadows, and
then save the image.
-Brian
Yes, but how would you handle creating the transparency level of the alpha
channel?
Brent
>>Yes, but how would you handle creating the transparency level of the alpha
>>channel?
Hi Brent,
If you habe the 3D Studio Special Effects book, you should carefully read
Martin Foster's Mountain Water effect starting on page 35. It is applicable
to what you are doing as well.
In short:
– Take the photo of your room into your favorite paint program. Paint all of
the floor areas touched by shadow pure black. Paint everything else pure
white.
– Place this image in the queue below the photo of the room with the floor
masked out.
– Use Queue RGB for Alpha with a Key Color of 255 and Blur edges ON.
– Use a Transition image of solid mid-gray to make the shadows
semi-transparent. You will need to experiment with a number of grays to get
just the right shadow transparency.
Reading Martin's effect should make the purpose of these steps crystal
clear.
Steven
Thanks alot Steven! I do have the book and I'll check it out. I see that
Murph is having Michelle Bousquette next week. I wanted to attend, but money
is tight and since I'm not a local the hotel/car doubles my expense. I'd love
to go though.
Cheers!
Brent
Brent:
>> I see that Murph is having Michelle Bousquette next week. <<
Hey! Hey! Hey! This is a familiar forum, can't have you talking like that
around here <GG>.
– Bob Ritger
Robert,
>> I see that Murph is having Michelle Bousquette next week. <<
But it's true, he is having me. But being the generous guy that he is, he's
sharing me with a roomful of 3DS students.
Michele
Wish I could video tape that…
<g>
-Alan
PS -Nice seeing you again at Siggraph! We've gotta keep meeting like
this… <g>
Alan,
Yes, it was fun listening to you blather on about all the other women at the
party… made me feel so wanted. <g> Wish I had gotten to dance with you and
Martin at the House of Blues.
Hey, you guys never showed up at the Autodesk Press reception Wednesday night.
Were you busy, tired, or just not interested?
Michele
I hope the seminar is fun for you Michele. I was able to attend last year when
Steven was the instructor. It can be a bit expensive since I'm not local.
Of course if the late money that I received last Friday had arrived a month ago
when it was due, I'd probably be there! Ahh, the trials of self-employment…
Have fun,
Brent Bonet – POP! Multimedia Atlanta
>> trials of self-employment… <<
Ah, but this just means you can hop in the car and come on up! A sort of 3DS
road trip. And David Mennenoh is going to assist in the class, since there are
eight students and only one of me.
But hey, we can always fit in #9… actually, we had originally put a ceiling
of ten on the class, which is why I got David to help out.
Michele
Michele:
>> But it's true, he is having me. But being the generous guy that he is, he's
sharing me with a roomful of 3DS students. <<
Yowsa! Makes me wish I had signed up for that course 🙂
– Bob Ritger
>>having Michelle…
I'm jealous – all I got was your foot! Well that and some of the
sure-to-be-classic tatoos.
A great time was had by all. Ack, back to work now!
JKJ
Use the image with only shadows (created manually with Photoshop) as an RGB
Intensity Alpha for the Floor image in the VP queue. The shadow image should
be a grayscale image that's completely white, with shadow areas being gray.
The floor image will be semi-transparent based on the darkness of the gray
areas in the shadow image. These semi-transparent areas of the floor will show
the default black background in VP, effectively darkening the floor in those
areas. You can then adjust the darkness of the shadows by adjusting the
darkness of the gray areas in the shadow image.
You will need another transparency map for the furniture image (line two in the
VP queue) based on the same methodology, so that it becomes transparent in the
areas where the floor should show through.
There other methods similar to the above, but most require roughly the same
amount of work to setup and do not allow for as easy shadow adjustment.
— James — Choreo Motion —