This document is created to provide clarity to all contributors submitting 2D CG Assets (e.g. computer generated but rendered as 2D images) for review by ActionVFX. The goal is to ensure all contributors are following the standards we hold for our own products, thus eliminating many rounds of review or rejection of a collection.
Important:
Not all guidelines will pertain to every collection that is being created.
This document will be updated from time to time.
Quality Control Criteria
General
This section covers the general practices when creating 2D CG Assets.
Achieving a Consistent Look
The main goal in creating CG assets is to ensure the look of the assets are consistent across the collection. Whether you choose photorealism or a more stylized look, the look itself should look the same throughout all clips.
Tips on creating a consistent look:
Be sure to look up examples of the asset you are going to create. Looking at various different examples to gather as much information as possible is key to achieving that consistency.
Ensure fine details (textures, lighting, reflections) mimic real-world counterparts.
Alpha Channel
The alpha channel should be created in a way that takes into account what areas of the asset should be opaque or semi-transparent. For example, a CG Tree should be fully opaque, and a CG Concrete Bullet Hit should have semi-transparent areas in the dust from the impact.
An example from the Assorted Trees collection. All areas of the tree itself are opaque.
An example from the Large Concrete Bullet Hits collection. The dust is semi-translucent in the thinning dust areas, and more opaque in the thicker areas.
Lighting & Shadows
The lighting of CG assets should be done in a way that makes the asset usable in many lighting conditions. A typical 3-point lighting set up is typically best as it ensures there is directionality to the lighting but it’s not too strong in any one direction. Including different lighting passes in the EXR versions of an asset can help give a compositor even more creative control.
Tips on creating useful lighting and shadows:
Light the asset in a way to where it works for many different lighting scenarios and environments.
Don’t place lights too close to your asset and ensure there are no hot spots.
Include different lighting passes to give an artist full artistic control.
A good example of a CG collection including different lighting passes is Assorted Trees.
Motion and Dynamics
Ensuring that your CG assets have natural motions is crucial in selling the realism of the asset.
Tips on natural motion:
Study real life examples of how your asset behaves in its natural movement. Keep physics in mind when achieving realistic movement. This includes: gravity, wind, and fluid dynamics.
Include motion vector passes when applicable.
Render Passes
Most CG Assets benefit from having an OpenEXR file that contains multiple layers for creative control in the compositing process.
Essential Render Passes for Most Effects
RGBA - Beauty pass with alpha channel
Light Passes - Individual light passes for main, fill, and rim lights.
Depth
Normals (Or RGB Light Pass for Volumes)
Shadows - A separate render with ground shadows. Essential for products like exploding debris that have complex interactions with the ground.
Non-essential Render Passes
Motion Vectors
Object ID / Masks - Masks for specific portions of the image such as Fire/Smoke masks for explosions or a mask of the inside surfaces of a large ground crack.
Volume Light - A light pass for volumetric lighting such as that which would be in an explosion.
UV - A pass allowing artists to re-texture surfaces.
Position
The Beauty Pass
The beauty pass (RGBA of the final EXR) should be able to be rebuilt by simply combining the provided render layers. For example, when merging the key, fill, and rim light passes of an element from the Assorted Trees collection with a plus operation, the “rebuilt beauty pass” will match the original beauty pass (rgba) perfectly.
Layer Names
Layer names should be left as default in most cases such as with Normals, Position, Depth, and other utility passes.
However, there are cases where the render layers should be renamed. This helps make the assets easier to use.
Examples:
Light Passes should use the following naming convention: light_[light_name]
i.e. “light_key”, “light_fill” and “light_rim”
Mask or Matte layers should use the following naming convention: mask_[mask_name]
i.e. “mask_fire” and “mask_smoke”
Frame Rate & Resolution
Make sure there is a consistent frame rate and resolution across the collection.
Tips for frame rate & resolution:
Make sure to choose a frame rate that makes sense for the collection, and that stays consistent from clip to clip. 30fps is the recommended lowest frame rate.
4K resolution (EXR) is the minimum resolution for all 2D elements.
4096x2160 or 2160x4096 depending on what makes the most sense for the asset/collection.
File Size Guidelines
Keep file sizes as low as possible while still delivering a high-quality product. File size is a very important aspect and should be top of mind when delivering assets for the Marketplace. If your files are too large, look into ways to reduce file size such as shortening the clip or removing uncommon render passes.
Refer to this chart to adhere to our file size guidelines.
Render Specifications
Video assets should be delivered to ActionVFX in the following formats:
4K Resolution - 16-bit OpenEXR (final high-quality render)
2K Resolution: ProRes LT (for quick previewing purposes of samples and drafts) or 16-bit OpenEXR (final high-quality render if applicable)
OpenEXR Render Settings
File Type | OpenEXR |
File Extension | .exr |
File Name Format | Clip_Name.####.exr |
Compression Type | ZIP-1 |
Bit Depth | 16-bit half float |
Color Space/Output Transform | ACES scene_linear (ACES - ACEScg) ACES is always preferred, but if the assets are not available in ACES then you should clearly state what color space the assets are delivered in when submitting them. |
Alpha Channel | Premultiplied Alpha if an alpha channel is available. |
Resolution | 4K DCI (4096x2160). This is the preferred delivery resolution, but we understand this may need to vary in some cases. Here are some other popular resolutions:
|
2K ProRes LT Preview Render Settings
These renders will be used solely for preview purposes by our internal team. It will help us preview and review your assets faster than if we only had access to the final EXR files.
File Type | MOV |
File Extension | .mov |
File Name Format | Clip_Name.mov |
Codec | Apple ProRes LT |
Color Space/Output Transform | Rec.709 (ACES Output - Rec.709) If the assets were not processed in ACES, then they should be delivered in Rec.709 or sRGB for the 2K ProRes LT preview. |
Resolution | 2K (2048x1080) will be the most common and is preferred, but HD (1920x1080) will be fine too if the resolution of your high-res version is 4K UHD.
The orientation of the preview renders should match your final renders. If your final renders are Portrait then your preview renders should be also. |
Image Noise
Final renders should be noise-free. Noise can detract from the overall quality and usability of the final output. If samples are not high enough, there will be noise present. Essentially, there should be no noise in the final renders.
Samples should be set high enough to ensure noiseless renders. Common areas that will produce noise are shadows and specular reflections.
Framing
This section covers framing practices to keep in mind when creating 2D CG Assets. The assets should utilize as much as the frame as possible. Nobody wants to purchase a clip of an explosion that only fills less than half of the frame.
Tips for framing:
Not all assets are meant to stay in frame. Sometimes it makes sense for assets to break frame. Think about what would be the most useful to a compositor when considering framing. For example, some elements such as Falling Snow or Rain make sense to break frame because they are most useful that way.
Good Framing
The asset is not breaking frame but is filling the frame.
Bad Framing
The asset is getting cut off due to breaking frame at the bottom of the frame. The asset should be centered horizontally and vertically.
If your asset moves across the frame or expands like an explosion, be sure to frame the final render in a way that captures the full element. This prevents the assets from being cut off by the edges of the frame.
Some assets need to break frame like those in the Falling Dust collection. If your asset must start off-frame and enter the frame, or start in frame and exit; keep it consistent throughout the collection.
Exposure
This section covers the typical exposure practices we take when creating a product. Typical exposure practices involve adjusting the brightness and contrast to achieve a balanced look that neither washes out details (overexposure) nor hides them in shadows (underexposure).
The goal is to produce assets with proper exposure that can be easily modified in post-production. This includes preserving highlights and shadow details to maximize the dynamic range and versatility of the asset. Proper exposure ensures that the VFX elements can be integrated into scenes with different lighting conditions without requiring extensive adjustments.
Properly Exposed
Underexposed
Overexposed
Submission Checklist
General
Background is clean
Render passes are included if applicable
Render passes are named using informative names
The Beauty Pass can be rebuilt 1 to 1 using the provided render passes
The assets have a clearly defined look that is consistent through the collection
The assets have natural motion
The collection has an alpha channel if applicable
The file size of each element follows File Size Guidelines
Submission adheres to the Render Specifications
Renders are high quality and noise-free
Framing
The assets utilize as much of the frame as possible
Assets are centered horizontally and vertically in the frame
The asset isn’t breaking frame unless it needs to
The first frame is black/empty if the effect is entering the frame or has a clear first frame such as with an explosion
Exposure & Lighting
The asset is not overexposed or underexposed
Highlight details are retained
File Size
The file size of each element follows File Size Guidelines
Render Specs
Submission adheres to the Render Specifications
File Uploading
Files are uploaded via MASV portal