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Old 08-01-2010   #1
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Default environemtn mapping and transparency

Hi,

Thanks in advance for assistance.

Ok - I have a wine glass on a table with a back ground flowers etc for a wedding still render.

What I want to do is to have the image of the newly wedded couple mapped on to the wine glass but maintaining transparency of the glass so the background is still visible.

So far I've tried env mapping which works but I dont want the couple seen in the background only on the glass surface.

Ive tried to use the env map tab in the maps drop down but its too faint and you cant seem to control the opacity of the environmental map - least I havent worked out how too.

I can place the picture as a decal on the glass but its not the effect I want.

Am I asking for the impossible??

So in a nutshell I want to render the wine glass which maintains transparency for the background objects but in the wine glass I want to see the reflection of the newly weds as if they were peering at the glass.

Ive done lots of reflections and refractions solid objects which work fine but never in glass and maintaining transparency.

Help is appreciated a nudge in the right direction would be appreciated.
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Old 08-01-2010   #2
BigFoot
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you can use the couple's image for global reflection map.and multiply it till you get the amount of reflection you need. or just in the glass shader you can put it as a reflection map.you'll still have the refraction you need.
which renderer are you using? vray can do this.

or another way would be making the wedding pic transparent in PS and then put it in the glass shader as diffuse map with no tiling.just make sure you use it as png with cutout edges so it doesn't look rectangularly unreal on the glass.
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Old 08-02-2010   #3
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Hey,

Thank you for replying,

Ok Global reflection map and multiplying it - that's something I haven't tried. I'm using MR as a by the by.. I've tried using the pic as a reflection map but didnt have a good result from that.

Ive also tried making the pic transparent in PS and using it as a png but it somehow just didnt look right not real world if you know what I mean.

I'll give global reflection a shot and see how that pans out.

Greatly appreciate the tip!!!
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Old 08-02-2010   #4
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easy way is to have the image of couple as a tex on a plane or cube position it in front of the glass.The image will reflect as long as you have reflective material on the glass.adjust the distance between objects until reflection is what you want.now position the camera in between the image and the glass and render
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Old 08-02-2010   #5
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Hi,

thank you for the reply,

Ok tried making the cube with the dearly loved "I hate em both now" :P and placing camera between the glass and cube behind.

Issues:

Cant get enough light bouncing back from the cube to get a good enough reflection.

If I use self illumination it effects the rest of the scene

If i get it too close and sort of come close to where I want to be the camera I start to loose the rest of the image so not enough space to get the shot that I want.

sigh

I really would like to work this one out and not be common and fall back on photoshop

I think the scene would be rather unique in concept..

Thank you for the suggestion none the less - its awesome that people are reading the post and replying..

cheers
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Old 08-02-2010   #6
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try to change lights like put a focused spotlight on the image or increase reflection of glass or change the channel you put the texture on .maybe go for the luminance channel instead of the color or add some glow.Also to increase your room select all object and change the size(scale) of the whole scene.thats all i got for ideas but i dont even know what the hell your working with anyway lol
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Old 08-02-2010   #7
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LOL - hey thanks again for the reply,

working with 3dsmax current,

It would have been easier if the object was solid - chrome ball box knife or spoon, but no it has to be glass.

Will try all of your suggestions, have already gone through a few last time..

I'm almost at the point of giving this away and put it in the too hard basket for now till lightning strikes.

Maybe even go back to pig farming :P..


cheers

I was thinking initially this was going to be a simple task
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Old 08-02-2010   #8
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post a screencap of your scene inside 3ds max or simply one of your rendered photos.it will be easier to get the right advice.
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Old 08-03-2010   #9
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Ambeint Oclussion on the reflection slot maybe?
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Old 08-03-2010   #10
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[QUOTE=curiosity;105802]LOL - hey thanks again for the reply,

working with 3dsmax current,

It would have been easier if the object was solid - chrome ball box knife or spoon, but no it has to be glass.





you are correct you really need a darker substrate I was going to say a wine /champagne bottle would be better
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Old 08-03-2010   #11
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Ok,

I've created another scene using a pocket watch not created by me, but perfect for showing and explaining what I'm trying to achieve. The pocket watch has a better surface a nice lid with glass which helps with trying to illustrate the issue.

The link for the file is below.


If I use thin wall glass then we get no refraction.

But I get close to the desired effect. Refraction is still needed to make the scene right.

Using thick wall glass I get the refraction but loose transparency.

I've put some random objects in the background for illustrating the issue.

I have tried various glass surfaces with no luck.

It would have been so simple if the 0 - 100 was enabled for the environment tab .

Link(s):
 
I've included two renders to save rendering the file of what the outcomes are.

Thanks in advance! and thanks for the replys so far!!!
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Old 08-05-2010   #12
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i dont think that would help ok I was doing a glass floor last night and figured out one way to increase reflection without loosing transparency-(i use c4d btw)put some white in the color channel and adjust the mix fairly low you really cant tell its colored
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Old 08-05-2010   #13
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Hey thanks for the reply,

I'll try that thank you,

I will add - since playing some more - unfortunately like a dog at a bone atm - I've come up with one solution. What I've done is taken the glass lid and made a clone of it - moved it from the original glass lid about .001 just enough so one glass lid is sitting on top of the other.

I've applied refraction only to the bottom glass lid and reflection only to the top glass lid and so far the best result I've gotten, actually good enough to be used as a final render for my project.

Surprisingly without extra overhead in rendering - or if there is any of no noticeable time added.

I'd still like to see if it could be done without having to have a double glaze so to speak.

cheers and thanks for the assist..
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