live 3d section video?

[Anonymous]

Is there a way, in AC11 or any other program, to take a model (made in AC11) and create a rendered movie of a section plane moving through the building?

In effect, much like moving a section plane through a model in SketchUp, but with the graphical output rendered rather than like SketchUp...

[Djordje]

laszlonagy wrote:

Djordje wrote:
AAAARGH! I am getting old ... can someone check whether there is a CUTPLANE GDL command?

Yes, it needs to be done with the CUTPLANE command the way Djordje described.

Do you still remember HOW? I checked with some GS veterans and they don't remember either ... 😉

[Karl Ottenstein]

Djordje wrote:
Do you still remember HOW? I checked with some GS veterans and they don't remember either ... 😉

The cutplane command inside a GDL object/script only affects elements generated by the object. So...I suspect that the 'old' method required that the entire building be saved as an object, and then the building object would be CALLed by the animated cutting plane object - which simply moved the cutting plane along a specified axis a specified amount (parameters) each time the animation frame (N_ in the old naming) changed.

Today, I would use SEOps and keep the model live. The cutting box object would just change its size dynamically by frame after initial parameter setup and physical positioning.

I don't have either method implemented...so these are just my ideas of how I would go about it. 😉

Cheers,
Karl

[Laszlo Nagy]

What I would do is:
1. Save the whole model as a GSM object.
2. At the beginning of the 3D Script, enter an ADDZ command (e.g. ADDZ CutHeight) CutHeight would be the current position of the Cutplane.

GLOB_FRAME_NR is a GDL Global that returns the frame number you are currently at during an animation. This needs to be used.

There would be a frame at which the CutPlane's height starts to change (StartFrame) and another at which it ends (EndFrame).
There are two height values for the position of the Cutplane at its beginning and ending position (StartHeight and EndHeight)

The CUTPLANE command always cuts by a X-Y plane and removes everything above the X-Y plane at the zero Z value level.

The CUTPLANE coomand precedes the 3d model data it must cut and after the 3d model data a CUTEND command must be placed.

So the script would be something like this:

HeightPerFrame = (EndHeight-StartHeight)/(EndFrame - StartFrame) !!!This is how much the Cutplane raises with each frame
IF GLOB_FRAME_NR>=StartFrame AND GLOB_FRAME_NR<=EndFrame THEN
CutHeight=StartHeight+(GLOB_FRAME_NR-StartFrame)*HeightPerFrame
ADDZ CutHeight
CUTPLANE
DEL 1
ENDIF

...
...
Here comes the saved 3D Geometry
...
...

IF GLOB_FRAME_NR>=StartFrame AND GLOB_FRAME_NR<=EndFrame THEN
CUTEND
ENDIF

The Rebuild Model for each Frame checkbox must be checked in the Create Fly-Through Dialog.

[Laszlo Nagy]

Karl wrote:
Today, I would use SEOps and keep the model live. The cutting box object would just change its size dynamically by frame after initial parameter setup and physical positioning.

I don't have either method implemented...so these are just my ideas of how I would go about it. 😉

Cheers,
Karl

Probably I would use the Cutting Box object, too, and SEO with it with upward extrusion.
The only problem is: the cutting must be visible during the generation of the Fly-Through, I guess (I would have to try), if cannot be on a hidden layer and still cut the building. Because if it is on a hiddel layer, it will not regenerate for each frame.
But if it is visible, its wireframe will show in the animation.
What do you think, Karl?

[Karl Ottenstein]

laszlonagy wrote:
Because if it is on a hiddel layer, it will not regenerate for each frame.
But if it is visible, its wireframe will show in the animation.
What do you think, Karl?

I have learned not to guess what will happen using logic, since what AC actually does vs what I expect it to do is a very often a surprise. 😉 If I took the time to test this...I would first see if indeed the cutting object on the hidden layer would be regenerated or not. Typically, yes, hidden elements would be ignored. But, since it is involved in an SEOp, I believe that AC should regenerate it since visible elements depend upon it and that dependence is explicit in the model. Maybe someone has time to test?

If it must be visible, then making it 100% transparent for Lightworks animation would be one option. For OpenGL / internal animations, yes, the wireframe would show as you say.

Cheers,
Karl

[Karl Ottenstein]

laszlonagy wrote:
Here comes the saved 3D Geometry

As in my other post (I think we typed at the same time!), a CALL to the object representing the saved model is better I think. Then, the entire cutting plane object becomes a parametric tool. You enter the name of the saved model object as a parameter, as well as params about the nature of the cutting and speed of animation. The resulting cutting object can be reused by anyone without requiring any further GDL programming. I think?

Cheers,
Karl

[Dwight]

Talk is cheap. Make some code that works. I can't.

[Karl Ottenstein]

I "love" it... taking a few minutes to test the concept, AC 11 build 1114 crashes when clicking on the compression settings button in the animation dialog. In GS's defense, I upgraded QuickTime today with the automatic Apple updater...so maybe something went wrong there.

Will post something if it'll work long enough to test, Dwight. And, hey, I'm not sure if talk is really that cheap. I charge as much for talk as for real work. 😉

Karl

[Dwight]

Thanks.

You could just do a simple model and "Show" instead of saving...

[Karl Ottenstein]

OK. Never mind the code. This is either a bug, or simply an oversight by the GS programmers.

I have a GDL 'box' that simply moves to the 'left' on the X axis 1 foot per frame. The SEOp subtract shows at the starting position. However, with the box completely visible (but on a wireframe layer in order to observe the behavior) and with the 'rebuild model for each frame' box checked, I can watch the wireframe move over my model, foot by foot, but the subtraction is not updated.

A further issue/bug is that when an animation is complete, the dynamic box's position is shown as it was in the last frame, yet the frame number is supposed to be reset to 0 and the 3D window rebuilt when an animation is complete. Manually rebuilding the 3D window has no effect. Closing the 3D window and reopening it is the only way I can get the window to rebuild properly. (It is not a display driver issue - it will rotate with the incorrect information shown. Why would 'rebuild' fail, yet closing and opening the window work?)

Attached is an image showing the 'cube' at frame 5 (5' into the model), but with the model cut at the original position of the exterior face. This is not even an animation at this point...but the 3D window.

So... I guess we're back to the save-model-as-object approach from years past.

Karl