tailieunhanh - From after effects to flash poetry in motion graphics - part 7

nên được thêm vào trong một layer mới (mỗi đối tượng trên một layer). Để tạo ra một layer mới, bạn bấm vào nút lệnh New có dấu +. - Để chèn nhạc, bạn cần phải tính toán số frame sao cho độ dài vừa đủ so với đoạn nhạc. | FROM AFTER EFFECTS TO FLASH POETRY IN MOTION GRAPHICS Set the Background layer as the parent of the Minute layer and if you move the clock 10 pixels to the left the arm moves the same distance. If the relationship between the clock and the arm was an absolute relationship the arm would move to the same location as the clock. What happened there was After Effects calculated the change in position between the Anchor point of the child and Origin point of the parent. What you really need to understand is that the Origin point is not the same as the Anchor point. The Origin point is the upper-left corner of a layer. If you click the clock face on the Comp the handle in the upper-left corner is the Origin point of the layer. The Origin point is the value of the Position point minus the Anchor point value. In the case of our clock the Origin point is located at 200 - 250 and 200 - 335 or -50 -135. If you still have the clock face selected this makes sense because the upper-left corner of layer is outside of the Comp area. The Origin point for any Comp is always the upper-left corner or the 0 0 point. This relationship is extremely important to understand because sometimes when a parent has multiple children you may move the position of the parent but the children don t appear to move in lockstep. The reason is the Anchor point the crosshairs in the center of the Comp of any object is relative to the layer while the Position property is relative to the Comp. In Figure 8-3 we have placed a solid that matches the 500X500 pixel size of the Comp. The Anchor point of the solid and its Position property are the same. Figure 8-3. Position and Anchor point are an exact match. 280 MEET THE PARENTS In Figure 8-4 we change the position to 300 300. Notice how the Position property changes but the Anchor Point property the intersection of the guides remains the same. What you can gather from this is the Anchor point is the pivot for all animation. Figure 8-4. Changing the solid s .