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Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: dzintas on 2022-02-20, 16:55:50

Title: 3ds max projection mapping
Post by: dzintas on 2022-02-20, 16:55:50
Hello, had a weird request from a client recently and got a little bit stumped recently.
Client want's to put images on sunshade facade elements and want to make that perspective trick where image only reveals itself when you're standing in specific spot.
So he wants our help with testing the images and help with documentation needed for the printing process.
Thing is i'm encountering a problem with uv mapping. I used planar mapping aligned to a camera view to simulate a projector in a way.
But because it's a planar mapping thing it still projects the image from a big plane, not from a single point as a projector does. Because of that I get stepped effect in some places witch is not desirable.
I tested it out with a spot light in max and worked pretty well.
So my question is. Is thera a way in max to project a texture from a single point like projector does or is it impossible?
Title: Re: 3ds max projection mapping
Post by: pokoy on 2022-02-20, 17:38:59
Yes, this would be camera mapping. You set a camera's position and orientation to where the viewer would be positioned, and assign a Camera Map modifier to the geometry. That way, the viewport and render will display the map as projected from the projection camera.
Another camera can then move freely and the image still projects from the projection camera.

Some problems with this - Your geometry needs to be subdivided in order to get distortion-free mapping in the viewport... but there always will be some distortion.
2 ways to overcome this:
1) Use a Camera Map per Pixel and nest the projection bitmap in there. Specify a camera, that's it. This will make the projection distortion-free, but only in rendering.
2) Use OSL's Projection Map, but that's only available with Max 2019+. This one should display correctly in the viewports (without the Camera Map modifier on the geometry) and should render correctly, too.

If you need to supply the individual elements to the printer you'll have to either bake the map (not sure how hassle-free baking will be and if it works well with OSL...), or to render each facade element individually from an ortho camera placed and oriented towards each respective facade element.

Hope this helps.
Title: Re: 3ds max projection mapping
Post by: dzintas on 2022-02-21, 08:28:57
Thanks a bunch!
Sounds promising, I will test this one out!
Title: Re: 3ds max projection mapping
Post by: DPS on 2022-04-01, 07:15:03
Yes, this would be camera mapping. You set a camera's position and orientation to where the viewer would be positioned, and assign a Camera Map modifier to the geometry. That way, the viewport and render will display the map as projected from the projection camera.
Another camera can then move freely and the image still projects from the projection camera.

Some problems with this - Your geometry needs to be subdivided in order to get distortion-free mapping in the viewport... but there always will be some distortion.
2 ways to overcome this:
1) Use a Camera Map per Pixel and nest the projection bitmap in there. Specify a camera, that's it. This will make the projection distortion-free, but only in rendering.
2) Use OSL's Projection Map, but that's only available with Max 2019+. This one should display correctly in the viewports (without the Camera Map modifier on the geometry) and should render correctly, too.

If you need to supply the individual elements to the printer you'll have to either bake the map (not sure how hassle-free baking will be and if it works well with OSL...), or to render each facade element individually from an ortho camera placed and oriented towards each respective facade element.

Hope this helps.

Where would I find the OSL projection node in Max 2020? I can't see it.
Title: Re: 3ds max projection mapping
Post by: swedgedesign on 2022-06-10, 17:49:57
Rather than starting a new topic, I thought I'd bump this

I've got a similar request, but for an anamorphic illusion on a digital display - I understand the texture projection using a camera map modifier but is there a way to have this projection using geometry?

So say I've got a plane for my screen, I want to then render what's behind the screen onto a texture for the screen if that makes sense?

The method I've got just now is to render from the camera as is, and then warp the footage so it is correct for input into the screen display