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Need real camera projection mapping


pixelplucker

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I noticed a couple big set backs using decals for camera projection mapping besides the spastic positioning of the decal which is easy enough to use the numeric inputs...

 

Low angled patches don't receive decals.

 

Decals only apply to what is visible in the scene so your limited to just what is initially in the scene.

 

Is there another way to do this besides decals?

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  • Hash Fellow
Decals only apply to what is visible in the scene so your limited to just what is initially in the scene.

 

that's a limitation of the technique... in any 3D program. If the camera needs to move so much that uncovered surfaces become an issue then they start painting something to put there, possibly cloning from the original image, and apply another decal.

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Okay, this'll be a stretch... but it's an option with a lot of possibilities in some particular situations.

The downside is that you'll have to do a lot of planning from the beginning that you might not do otherwise.

 

Light Gels. (See page 100-101 of the A:M Technical Reference for general setup and information)

 

In order for this to work in the same fashion as camera projection you'll likely need to keep all your effected lights and models in grayscale (mid gray color should work best). This counters the loss of imagery projected due to the nature of Light Gels, where black color blocks light from projecting.

 

One of the benefits is that this method tends to wrap the image around the object wherever the light touches.

Another is that every object in the scene recieves the projected imagery.

Another is that you can use this with Light Lists. (Note: I'd need to test this as I don't recall ever trying this)

Yet another is that you can use Materials in place of the images as your light gels.

 

Someone with an actual clue could probably figure out how to wrap multiple projections via an array of lights all the way around the focal point in a scene. I duly qualify as clueless and am out of my league so will defer to the experts on this.

 

Not sure about all of this but as far as I can tell this would address your trouble areas:

Low angled patches don't receive decals.
Check!

 

Decals only apply to what is visible in the scene so your limited to just what

is initially in the scene.

Check!

 

Edit: There are several ways to turn the images on/off in a Light Gel. One is to toggle off the Diffuse setting or 'Light Default Models' in the Light. Another more esoteric switch might be to use a sequence of images and the timing setting of the image to move to a frame with a transparent image.

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  • Hash Fellow
Wait for a second...

 

For years I've been trying to do some camera projection mapping in A:M.

 

How do you do this?

 

An object is in your camera view....

 

Select the object in the Objects folder and RMB>New>Decal

 

The decal will appear in the camera view for you to position and apply on the object. The bounding box is very jittery in this view.

 

And:

What are light gels?!

Never heard of this!

 

Drag an image onto a light and the light will project the image like a slide projector. Good also for making non-circular light patterns.

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I can sense the cool stuff SoulCage can create using projection mapping and light gels so I'm thrilled this topic came up.

 

Drag an image onto a light and the light will project the image like a slide projector. Good also for making non-circular light patterns.

 

I have noticed occasions where dragging and dropping images onto a light didn't seem to work. This was likely user error on my part or I simply had my lights set up wrong, but all I knew at the time was that I wasn't getting the results I wanted. When I followed the guidance in the Tech Ref and Right Click'd on the Light and then added an image from the listing of available images, I've always got the right results.

 

Note: Light Gels aren't just restricted to usage in Choreographies. They can be applied just as effectively, if not more so, via Actions.

 

While I fully understand camera projection has taken on different methodologies in the realm of digital film and CG, 'real' camera projection has historically been accomplished through the projection of light.

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Is it possible to make an ignore list or inclusive list for a particular light on particular objects?

If not then I would have to render one scene with the light gel then render another with the other objects and post them together.

 

My other option is to down sample my hd capture to standard vga in order to get the whole scene decal-ed.

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Is it possible to make an ignore list or inclusive list for a particular light on particular objects?

 

Are you familiar with Light Lists?

I believe that is what you are after.

 

From page 178 of the Tech Ref:

 

Light Lists.

 

Light Lists allow you to have isolated lighting for specified models in a choreography. This allows you to exclude lights from characters or props. If you want the model to be lit by specific lights in the scene, create a light list in the model with only the lights that you want. Lights can be set to light all models, or only models with that light in its light list by changing the "Light All Models" property of the light. By default, a model has no light list, and therefore is lit by all lights in the scene that have "Light All Models" set.

To create a new light list for a model, in the Project Workspace, drag the Light Shortcut icon you want to add and drop it onto the Model Shortcut icon you want to add to. The "New Light List" dialog will appear. The "Start With" option determines whether you just add the single light, or all of the lights in the choreography with "Light All Models" set. If you are adding just a few lights, select "Only This Light", and drag each light onto the model. The New Light List dialog will only appear the first time when the list is created. If you select "Current Lighting", all of the lights that have the "Light All Models" property set will be added to the light list. You can then delete unwanted lights from the list in the Project Workspace. Check "Exclude The Light From Models Without Light Lists" if you do not want this light affect other models in the scene that do not have light lists. This is most useful when you create a light that only lights this specific model.

 

Note: It's possible Light Lists may have changed since this description was written but they should still operate in the same or similar fashion.

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Was looking that up, having trouble with gels working, probably my fault.

Right clicked on the shortcut to my klieg light, added rotoscope and nothing shows. Changing light type also doesn't seem to work.

Still using 15j and had problems with decals on the ground and ended up making a new model for ground. Added objects also don't show the gel.

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I recall some of the problems I had initially with Light gels.

 

If your objects have a surface color you may want to change that color to a neutral gray. I've found they also work well with white but black... not so much. A black surface will absorb the light.

 

Also, consider turning down the intensity of the light.

*and use a Klieg light*

 

When in doubt start/test with a very simple object. The simpler the better when starting. (I often need this reminder)

Once you've got that basic project working expand it's complexity and explore all the v ariables.

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Some reason I had trouble getting the roto to apply but it applied ok from the list and not within the scene.

Just one last snag. Because I have some camera motion and need to track it to the scene I need to render to see the gel or I can't see what I'm working on to tweak object shapes and align AM's camera to the scene. Any work arounds on that one? :huh:

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Some reason I had trouble getting the roto to apply but it applied ok from the list and not within the scene.

Just one last snag. Because I have some camera motion and need to track it to the scene I need to render to see the gel or I can't see what I'm working on to tweak object shapes and align AM's camera to the scene. Any work arounds on that one? :huh:

 

I may not understand what you are doing - but perhaps a camera rotoscope (front projected on the ground, objects) would work better for you?

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I have some footage that I wanted to project onto some objects to add depth, capture shadows etc of a model I wanted to bring into the scene. Typical usage of camera projection mapping. Using a light gel is a nice effect but seems too lossy and the aspect ration is wrong.

 

Camera roto seems to be the same as camera projection, just named different? How do you set up an include or exclude for that so I can bring the model into the scene and have it not catch the roto?

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It's working as it should, just named different. So Camera roto is the same as Camera Projection map.

Tricky part now is matching up my camera angles to am's camera. Used a home hd camera so there is no real way of knowing what the zoom was etc. Subtle movements shouldn't be too bad since I can tween and tween and tween.

 

I do have to work in wire frame to see the roto and the models but this actually works out pretty well and I'm able to tweak the models for shape. Much easier than the last time I did this where I had an external modeler and would have to toss renders back to the modeler.

 

Thanks for all your help.

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Objects in the scene that receive the camera roto remain static. The AM camera position focal length and rotation move across the scene matching the objects to the roto. This allows me to animate against real footage and be able to have shadows, reflections etc interact with the footage as well as allows me to move the character from behind an object and have it run on top.

 

Wondering if there is any camera tracking software that can interpret from real footage and translate the AM camera.. any free stuff out there?

 

Be cool if AM Track could do this.

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Stian seems to use (or used) pfhoe (not free - but reasonable price)

 

http://www.hash.com/forums/index.php?s=&am...st&p=241599

 

http://www.hash.com/forums/index.php?s=&am...st&p=303610

 

I did a search on "motion tracking" as well as "camera tracking"

Edited by NancyGormezano
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Stian seems to use (or used) pfhoe (not free - but reasonable price)

Yeah, I am still using PFHoe. I absolutely recommend it. You don't get the tweaking options the big guys do have, but PFHoe is very easy to use and do a great job most of the times

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Saving my $$$ at this point since I have some stuff I need to invest in for my business. I did find Voodoo but it doesn't support AM directly. I makes .cam files but those aren't compatible and was wondering if it is possible to convert a text file into something AM can use?

 

Other exports it has is for Maya, Max, Lightwave, XSI and Blender but Blenders latest version is broken.

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