[Darby Edelen]

[Jason James] “This movement is called what? is it called a ‘Boomarang’ movement or something else? But ive already changed my keyframes to linear from bezier intorpolation.”

Double check that your Spatial interpolation is set to Linear.

Darby Edelen

[Darby Edelen]

This takes some knowledge of the order of operations (specifically blending) in AE.

In the pre-comp you are ‘Add’-ing the reflection and lighting passes to the global illumination pass, but then in the Main Comp all of that information is being blended ‘Normal’-ly with the shadow and background passes. The alphas of the 3 passes in the pre-comp are being added together before the normal blend in the main comp. In addition the color values at the edges actually end up being darker than you’d expect because in the area where the alpha blending occurs in the main comp the additive passes are not added to the background, but rather blended normally. This is simply due to AE’s rendering.

There are 2 solutions for this problem.

The first is easy and more accurate, simply enable Continuously Rasterize/Collapse Transformations on the pre-comp layer in the main comp, however this will break if you apply any effects to the pre-comp layer.

The second takes a few steps and results in a slightly less pristine edge:

1. Enable the Layer > Preserve Transparency switch on the 2 additive layers inside the pre-comp. This will eliminate the additive build up of the alpha on the edges and should improve your results some.

2. To deal with the darkening of the color values you can apply the Channel > Remove Color Matting effect to the pre-comp layer in the main comp. This will result in some overbright values at the very fringes of the layer so apply the Channel > Set Matte effect to matte those out.

I’ll also add that I don’t usually run into the issue you’re having here when using Unmult through the EXtractoR effect so I have a suspicion that there may be better render settings for AE in your 3D package that won’t require the above workarounds.

Darby Edelen

[Darby Edelen]

Instead of generating the random frames in the 5 frame comp, or in addition to that, apply time remapping to the pre-comp in the parent composition and apply another random() function there. Something to the effect of:

source = thisLayer.source;
d = source.frameDuration;
frames = source.duration / d;
random(0, frames) * d;

This will first find the duration of the source (the pre-comp) which in our example is 5 frames. Then it will randomly generate a number between 0 and 5 on every frame of the composition. This will occur across the entire duration of the parent composition. So you’d get a random frame from your 5 frame set on every frame.

Darby Edelen

[Darby Edelen]

[Walter Soyka] “zoom = thisComp.width/(2*Math.tan(degreesToRadians(FOV/2)));”

Walter’s expression is perfect for a horizontal FOV, which is generally the most common. However, the data from your 3D camera may be stored as a vertical or diagonal FOV in which case the expression will vary slightly:

Vertical

zoom = thisComp.height /(2*Math.tan(degreesToRadians(FOV/2)));

Diagonal

w = thisComp.width;
h = thisComp.height;
d = Math.sqrt((w * w) / (h * h));
zoom = d /(2*Math.tan(degreesToRadians(FOV/2)));

Darby Edelen

[Darby Edelen]

Oh man, I just got this… Nice Jacob, Nice.

Darby Edelen

[Darby Edelen]

My last ditch effort would be to solo the offending pre-comp and the background, if the problem still persists turn off any effects on the pre-comp, if it still persists make sure there are no layer styles that got mysteriously applied.

If you could post screen shots of the problem layers both inside and outside the pre-comp that might help deduce the issue as well.

Darby Edelen

[Darby Edelen]

There’s also the rgbToHsl() and hslToRgb() functions to help. Get the hue of the color chosen in the colour picker then apply it to the colours of the 4 color gradient.

You could also drive a HSL effect applied after the 4 color gradient with these functions (but that effect is not 32bpc compatible).

If you don’t mind splitting the operation into 2 layers and using the Fill effect (or maybe just using the Solid Composite effect) with the Hue blend mode that’d be an easy way to go as well.

Darby Edelen

[Darby Edelen]

I think I’m not understanding the final goal. If your sequence (pre-comp?) is 10 frames long then you’ll always only have 10 frames to randomly select from. If you enable time remapping and randomly select a new frame on every frame then you’d get exactly that: a frame chosen from the set of 10 total frames on every frame of the comp.

The way I understood your initial question was that you have a set of random frames, you want them to loop but have a new randomized set on every loop. Imagine there are 5 frames, we’ll letter them A-E, then your current random sequence could be:

DADBA

Now you want to generate a new set of random frames for the next loop and we get:

ABEDD

So your two loops together read DADBAABEDD. Couldn’t that be generated just by selecting a new random frame at every frame?

I’ve probably misunderstood the premise and your goal, but I need clarification to understand it. Are you hoping to generate random non-repeating sequences? For example:

DAEBC

AEDCB

Where each frame occurs only once? If possible share your current expression and how you’d like its behavior to change.

Darby Edelen

[Darby Edelen]

[Sasha Zelman] “Is there a way to loop short composition, that was previously Time Remaped to produce random frames, in such a manner so random seeds change between the loops and produce new random loops?”

I can’t think of a way off the top of my head.

If you’re randomizing something that’s already random though, wouldn’t the results just be… random? To put that another way: why do you need to loop at all? Why not just generate random numbers?

Perhaps there’s another way to achieve the result you want. What is the goal?

Darby Edelen

[Darby Edelen]

[William Marler] “Is it possible to “split” the swatch into the different values like you can split dimensions in the position parameter? If not, is there some way of changing the colour of a layer through RGB parameters as opposed to choosing a swatch with the colour picker.”

You can do this with an expression. Color is stored as a 4 component array (or vector), so if you applied this to any Color Swatch you could produce different colors using RGB values:

50% Gray:
r = 0.5;
g = 0.5;
b = 0.5;
a = 1.0;
[r,g,b,a];

100% Red:
r = 1;
g = 0;
b = 0;
a = 1.0;
[r,g,b,a];

Instead of manually entering the values into the expression you could aaply an Effect > Expression Controls > 3D Point Control and point the expression to those values for the RGB components (alpha will generally be 1.0):

rgb = effect("3D Point Control")("3D Point");
a = 1.0;
rgb + [0,0,0,a];

Note that internally all RGB values are in float (0.0 = black, 1.0 = white). If you wanted to supply 8 bit code values then you’d need to divide them by 255 to get the correct float value:

rgb = effect("3D Point Control")("3D Point") / 255;
a = 1.0;
rgb + [0,0,0,a];

Darby Edelen