PDA

View Full Version : Four corner pinning


Douglask
05-07-2003, 03:56 AM
Hey guys, almost have no hair left because of this one...

In combustion 1 there was an option where you had to select a Layer to become Four-Cornered. All you would do next would be to select your toolbar and highlight the little four-corner dot Icon.

In Combustion 2 does this method even exist anymore? Maybe it's just my computer playing evil tricks on me but I don't see that Four Corner "Icon" anymore. note: the Four-Corner under Layer is still there, I'm just looking for that icon in the toolbar so I can get my track on!

Anyone have any ideas?

Cheers!

rodders
05-07-2003, 05:08 AM
Hi Douglas.
I have never used combustion 1 so i can't help you on icon bit.
but if you still want to use the four corner pin,just click on the layer you want to use in your workspace,then go to your composite controls,click the layer button,then the four corner pin button,you should now be able to see in your viewpoint the four corner boxes surrounding your layer,you now shift+click each box to select them.now you can go to the tracker,select the source,you should now be able to see the words ( track 4 control points,and away you go,don't forget to turn the animate button on.
good luck.
Rod

Jack Pfeiffer
05-07-2003, 09:17 AM
Hi...

Here is a quick tip on how to do four Point Tracking. Note that Four Point Pinning allows you to paste a still on something, like a new sign on the side of a truck, whereas, Four Point Tracking allows you to paste and then track a sign on the side of a MOVING Truck.

Here are the simple steps to do this.

1) Create a New Workspace: click File>New. Enter the parameters, for example: Type: Composite and be sure to activate 3D. - Name: Give your project a name. Format Options: for example, set to: PAL D1 -Discreet edit, PAL: 720 x 576, 4:3 Duration: Set the duration - 2D/3D Button: choose 3D. Bit Depth: set to 8 bit. Click OK: And your new Workspace is created.

2) Importing Footage: Next, you import two video layers to your Composite workspace. Click File | Import Footage, or press Ctrl+I (Windows.) For this example let's use a layer called TRUCK and a layer called LOGO.

3) Four Corner: Click and Select the Layer that you want to RESIZE and PLACE (LOGO.) Be sure it is at the top of the stack (top of the Timeline layer.) If is not at the top, in the Workspace (or Timeline) use you mouse to drag and move it to the top of the stack. Next, with the clip still selected, under the Composite Controls > Layer Tab, turn ON the “four Corner” button. In your viewport, the layer will have a LARGE POINT in EACH corner.

4) Corner-Placement: Now, with your mouse, you can select and MOVE each POINT of each corner, allowing you to place and pin each corner in the position that you want it placed at the start of the tracking. (If you can't see your layer, it is NOT on TOP!)

5) TRACKING four POINTS: You can track ALL 4 Points, but you must FIRST Select All four Points: With your SHIFT Key Depressed, CLICK with your mouse EACH of the four Points, starting with the upper right in a Counter-CLOCKWISE direction. Each Point will turn YELLOW to indicate that they have been selected. Note: you should ALWAYS click the corner points in the SAME ORDER, or you may later risk improper tracking.

6) Activate Trackers: Still with ALL four Corner points selected (turned yellow) Select the TRACKER TAB – and choose the background layer (source) that you wish to track (in our example, the VAN layer.) Set the Tracker POSITION -- You will see the four TRACKERS appear in the MENU as well as on your Viewport.

7) Position Each Tracker: With your mouse, position each tracker on each of the image points that you wish to follow (track.) Next, review and set the TRACKER Options as required and pertinent to your tracking requirements.

Here is a summary of important TRACKER terms, options, and exactly what they mean:

Axis: X & Y tracks both the X and Y axis, or one can track either only X or Y only.
Mode - Absolute: When you wish to place your psotion ON TOP of the track point. There will be NO offset. For example, when the tracker analysis starts, your point is automatically positioned to the center of the reference box on the asterisk.
Mode - Relative: Maintains a spatial offset between the tracker reference and the layer. Forexample, you track a point NEAR the position, while retaining an offset from the center of the reference box on the asterisk. This is the default setting.
Reference - Fixed: Designed when there is little or NO change in a track point: This leaves the contents of the reference box unchanged during tracking and is faster than Roaming, although it is less flexible, since it assumes little or no change.
Reference - Roaming: When the Track Reference CHANGES, this will update the contents of the reference box at each frame. Use this option when the reference feature undergoes significant changes in luma or shape cues during the clip. For example, if the reference feature undergoes lighting changes, choosing Roaming increases the chances of finding a match at each frame. Note that Roaming is slower than Fixed since the reference box must be updated at each frame and the Roaming results are often not as accurate because very small errors in the analysis are compounded.
Tolerance: Set your Tolerance to accommodate error there is in locating a match for the reference box. A keyframe is only set for the frame if a match is found. If Tolerance is set to 100%, a match is always found, regardless of how wrong it may be. If Tolerance is set to 0%, a keyframe is ONLY set for the frame if an exact match for the reference box is found. I suggest starting with Tolerance set to 100%, and then lowering it, as necessary.
You should reduce the tolerance value if the reference feature becomes hidden by another object for several frames and does not change direction during that time. This prevents the Tracker from setting incorrect keyframes while the reference feature is hidden. Adjusting the tolerance value can prevent or reduce the need to track manually. The Tracker can guess (extrapolate) likely future locations of the reference feature, while it is out of view.

For example, say a truck enters the frame from the left in your clip. After several frames a tree blocks the view of the truck. Then, after several frames, the truck reappears. You can use the headlight on the truck as a reference feature. You then pause the analysis as the headlight gets hidden by the tree, lower the tolerance until the Tracker cannot find a match, and then restart the analysis. When the headlight reappears, the tracker box is positioned over it, the Tracker finds a match, sets a keyframe, and continues tracking. Note that the Tolerance is "animatable". That is, you can change the tolerance value at different points during the analysis.

Using a Roaming Reference Box: You can choose to use a “Roaming” reference box when the reference feature changes gradually from the first frame to the last frame. To use a roaming reference box: In the viewport, select the reference box(es) that you want to set to roaming. On the Tracker panel, select Roaming from the Reference list. The reference box(es) will be updated at each frame with the contents of the match found in the frame. In other words, the Tracker will always look for a match of the reference feature from the previous frame.

8) Tracker Analyze with four Trackers: Next, you will need to select all the trackers and start your analyzing: Hold the SHIFT key and, in the viewport with your mouse, click and select all four of the Tracker Boxes -- Important! You must click in the SAME ORDER as when you created the corner points. Once they are all selected, you can start with the Track Analyzing. Click the Track Analyze button, and remember that you can track one frame at a time – forward or backward. (Note that the tracker will automatically mute and hide the layer to be tracker, in order to keep it out of view.)

9) SEE the Results: To see how the tracks have been applied, back on your timeline, activate the layer that was muted, in our example the Logo layer. Then, using the frame stepper, you can see the results, and you can adjust frames as necessary. Always remember to ADD A BLUR FILTER to better match the image to the moving background.

Happy Tracking !

(By the way - This is from my WebWarrior Combustion Book -- more info at: http://www.mci.dk/combustion)

Jack Pfeiffer
host at - www.creativecow.net - www.vfxtalk.com - www.fxguide.com
- combustion demo artist & trainer - secretary of the danish discreet user group

Douglask
05-07-2003, 05:42 PM
Thanks guys, well good news that they simplified the 4 point in vers 2.0! and here I was going nuts looking for a tiny icon that doesn't even exist anymore...go me! lol.

Cheers!

1armedScissor
05-08-2003, 02:08 AM
one more tip when working with 4 corner pinning or tracking in combustion 2 is that you have to have your resolution set to "preview" or "best" otherwise you won't be able to move each point independently of the others.

CGTalk Moderation
01-15-2006, 12:00 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.