RG Corner Pin plug-in: Detail controls

This page lists the controls in Corner Pin that support or assist the results of the pinning. The controls that we will talk about on this page are a mixed bunch, but they all add up to the same purpose: Making your pin look as tight as possible while giving you the flexibility you need to get the job done. Below we discuss the Transform Settings group, the Motion Blur group, and Opacity/Mode controls.

Transform Settings group

This group of three controls deals with settings that help you to see and render your pinned project.

Transform Settings> Quality

There are four modes for Quality. Low and Medium are workflow settings. They let you process up your composite quickly to see how things work. High and Super Sample (the default) are the options that you will choose for rendering. Choose High for projects that scale up the input image and Super Sample for projects that scale it down.

- Low: A ‘point sample’. It will sizzle quite a bit, when it animates you will see some sparkly artifacts, because it’s using a low quality sampling algorithm, but it’s very fast.
- Medium: A simple bilinear scale. Looks okay, but it’s a little soft. Similar to the quality you get in Photoshop’s Image Size.
- High: A modified bicubic sharpening filter so it’s sharp. Particularly good if you have a small input source and you’re mapping it to a larger output source. It’s good if you are scaling up the output. At High we get a lot of sharpness but the lines look very aliased.
- Super Sample: This does a fancy multi-sampling of the image to try to smooth out the edges and smooth out the interior data so that you don’t get any sparkling or sizzle in the animation, or any noticeable anti-aliasing. When something gets very small, if you get a lot of high frequencies or sharp edges, the artifacts will be very noticeable. If I move forward in the animation and zoom up to 800%, you can see the difference. Super Sample is good if you have something large that you are animating down to be very small. Unlike High, Super Sample is going to smooth out the high frequency and there’s extra anti-aliasing around the edges. Super Sample tries to use more samples around each pixel to make the image look smoother when you scale it really small.

More about Quality> Super Sample

The Super Sample algorithm is very smart. If you have Super Sample chosen, it will blend to High when the image is above 100% of its original size. If you have High chosen, it will blend down to Super Sample when the image hits below 100% of its original size. This would typically be when an object is animating into a new position, the input image is scaled up very large or larger than the source size, and then the object is animated down into something very small.

For instance, a bus is moving from the foreground into the distance, and the poster that is corner pinned to its side needs to follow the perspective. It compensates for the image being sharp when it’s big, but not get sizzly as it gets smaller. So Super Sample is a blended quality mode. It will use High when the image is big. When the image falls below 100%, Super Sample slowly blends in more pixels to the output to make the image look smooth.

When you select Super Sample from the Quality popup, two controls become active, Super Sample Softness and Super Sample Edge.

Transform Settings> Grow Bounds

Grow Bounds is an interesting and very useful setting. This control extends the size of the input area, as measured in pixels. Grow Bounds expands the boundaries of the graphic as if it is making a larger bounding box.

In the case of a layer input that needs to be larger than the output, if you have cropping of the layer and you want extra pixels outside of it, then Grow Bounds will add extra pixels around the outside of the layer. Technically it adds black opaque pixels around the outside of the layer, which becomes part of the alpha channel, which extends the layer size. It adds a border region around your image. The limit is something crazy big, like 5,000 pixels.

If Grow Bounds is set to 50, then the boundaries are 50 pixels larger, with 25 pixels added to each side, left and right and up and down. At 200, it's creating an extra 200 pixels around the input image, with 100 extra pixels on each side.

In our example, we have brought in a Flower graphic at two different sizes. One is 600 pixels wide, one is 1,000 pixels wide. The 600 pixel Flower is large enough to fill the Billboard's pin area, but not once the warp perspective is applied, so it gets chopped off along the right hand side. By changing Grow Bounds from 0 to 100, we extend the bounding box of the Flower and allow the whole image to show against the Billboard.

Transform Settings> Super Sample Softness

Activated by choosing the Super Sample mode in the Transform> Quality pop-up. Super Sample Softness controls the balance of sharpness to softness when the corner pin size becomes very small. The Super Sample mode will try to minimize the high-frequency detail when the To Pins cover a very small area. This prevents visual artifacts that appear as sizzling or line pulsing when the input image is scaled to a very small size.

The default of 1.0 is a good balance of smoothness between sharpness and smoothness. You can enter a lower value and the image will appear sharper. Values below 0.5 are not recommended for very small images. You can also enter a value greater than one to increase the smoothing, which can be useful for blending corner pin composites into a background that is soft due to depth of field or other effects. The maximum value is 5.

Transform Settings> Super Sample Edge

Activated by choosing the Super Sample mode in the Transform> Quality pop-up. The Edge Super Sample feathers the edge of the alpha. It does not affect the image itself, just the alpha. This allows you to precisely control the edge ONLY and gives you control over the sampling of the edge on the alpha channel. Edge = 1 shrink to 1/32 of the alpha. The edge slider is smooth and does not choke the image.

Together with Super Sample Softness, this setting gives you precise control over your pin. This control is great for maintaining the quality of corner-pinning for small sized transforms. The maximum is a value of 12.

Transform Settings> Wireframe

Another view option, this time for seeing the wireframe that shows what the To Pins and From Pins are doing. Always On means always show the wireframe. Always Off means never show it. On (the default) causes it to appear when it’s selected.

The main difference you’ll find between On and Always On is this: When Always On is selected, when you click into the Project Window, the wireframe and pin labels will automatically show. When On is selected, they won’t show until you activate a control, like clicking on the Top Pins> Upper Left control.

Source Opacity

By default, Source Opacity is grayed out. The control becomes active when any Transfer Mode other than None (the default) is chosen.

Corner Pin Opacity

Corner Pin Opacity lets you set the transparency level of From image that you are pinning. It can be difficult otherwise to see the underlying target image that you are pointing to.

By default, Transfer Mode is set to None, and the To Pins group and Corner Pin Opacity are active.

Left to right: Corner Pin Opacity at 70, Opacity at 100. At 70%, the Flower graphic is semi-transparent, which allows us to easily see and pin to the underlying Billboard graphic.

Transfer Mode pop-up

Corner Pin includes standard transfer modes.

None: If Transfer Mode is set to None (the default), then you don't see any interaction between luminance values. Also, the Corner Pin Opacity setting is set to 100 and Source Opacity is grayed out. This is because the plug-in is always going to assume that you’re not comping over your source, so it respects the mask of the input, does no opacity change, and results in the output of the warp.

All other modes: If any other Transfer Mode is set, you get the activation of Source Opacity and the ability to multi-comp. This means we can comp from the input points with the output; this gives you, essentially, the non-perspective version and the perspective version layered on each other. The source is the From and the To is the corner pin. We can control those independently. Once a transfer mode other than None is set, we can play around with the two Opacity levels (Source and Corner Pin) and use our blending modes to add things together.

The main use would be to cross-fade between the warped version and the non-warped version. For instance, could make an interesting effect if you are trying to flash something on and off the billboard.

If you want to show what it starts out as and what it becomes, you can do a cross-fade of Source Opacity from 100 to 0 and Corner Pin Opacity from 0 to 100, and they would fade out across each other. Depending upon what Transfer Mode is selected, you’ll see more dark pixels or more light pixels.