Create Crowds in iClone Using Re-meshed Characters from Character Creator
In this article, Adolf Navarro, Director at Antareus Ltd., gives a walkthrough of his process for using Character Creator 3 and iClone to create a crowd scene with good quality and animation performance.
Digital humans for 3D projects are able to be made faster and better these days, but when a project calls for a crowd scene it can become difficult to manage due to the intense polycount accumulated among the characters.
The InstaLOD Remesher function of Character Creator can create several poly reduced versions of the same character, while the InstaLOD Polygon Reduction function can optimize the polygon count for all wearables on the characters. The optimized characters are animation-ready for the use with iClone, Unreal Engine 4, Unity or any other 3D tools.
Previously, Video was an Alternative, but with Limited Features
One solution is the use of billboards using popvideos as a texture. Each billboard can have several characters performing animations that have been previously rendered in other iClone projects. This is quite effective, but has the limitation that the billboards have to face the camera all the time, so it’s only useful for certain shots. If we make camera rotations or a long camera traveling, the trick is exposed.
Optimize Character Level of Detail (LOD) with InstaLOD in Character Creator 3
The fact is that when animating crowds, most of the characters are far away from the camera, so it doesn’t make sense to use the same quality for the characters that are close to the camera, Character Creator exports characters to iClone using the “InstaLOD remesher” option that can create several poly reduced versions of the same character.
Rationally Optimize Characters to Keep Balance between Quality and Performance
These reduced characters can be used in the iClone projects, Unreal, Unity or other 3D tools use different levels of reduction depending on the proximity to the camera. The further away the character is from the camera view, the less quality is required and therefore the simpler and lighter the character can be.
Significant Improvement in File Size and Framerate
Using the poly reduced characters from CC3 and InstaLOD, iClone’s performance gets boosted as it has to manage fewer polygons and textures. For example, a platoon of just 24 characters at standard quality, becomes very heavy and hard to handle occupying almost 1 Gigabyte of the hard disk, but replacing the characters with the exported ones using the “InstaLOD remesher – Normal” option, we can realize an important improvement in iClone’s FPS performance when playing the animation in real time. Also, the size of the saved project is reduced to a third of the original one.
Optimized Characters Ready for iClone Animation
One great feature of these reduced characters is that they can be animated with the standard tools of iClone. Even the reach effectors are still operative. So we can apply motion clips and edit their motions in the timeline.
Game Base & Polygon Reduction – Retain Visual Quality and Support Facial and Body Animation
If we need more quality in the re-meshed characters, Character Creator provides the “Convert to Game Base” tool that reduces the number of polygons of the character’s body and unifies its body textures in a single one. The “Polygon Reduction” tool can be used to reduce the polygons in the clothes and accessories attached to the character. Using these methods we can obtain a new reduced character that still looks pretty good, even at close range, and its clothes and accessories are still independent objects that can be saved and used in other characters and projects.
Some Tips to Make Crowd Animations Easier in iClone
Tip 1: Remeshing the Character without Accessories Attached to Keep Visual and Flexibility
Characters reduced using the “Export LOD re-meshing” tool, are re-meshed with all their clothes and attached accessories, making a unified single mesh, and sometimes it can create undesired results. In these cases, we can reduce the polygon of accessories independently by using the InstaLOD Polygon reduction tool. After the objects have been optimized, they can be saved and exported as and iAccessory in order to be used in iClone. Then, we can remove the accessories from the character, and export it to iAvatar format using the “InstaLOD Remesher”. Once the reduced character it’s been loaded in iClone, we can attach the previously re-meshed accessories to it. In this way, the re-meshed character is a little bigger, but all the accessories look good as they have not been melted with the character mesh.
Tip 2: Duplicating Characters and Motions for Crowds
Some motion clips like the ones created by the Puppet tool of iClone, actually don’t change the position of the character. In these cases, we have to create two transform keys, one setting the initial place of the motion and another one setting the final position.
When copying the character with its motion, it’s better to previously save the motion and their transform keys by using the collect clip tool. If not, when we copy the character using the move gizmo while keeping the CTRL key pressed, we’ll change the initial point of the motion for the new character but not the last one, so both characters will end in the same place. Instead, if we make a copy of the character with the loaded motion clip in a new position, the displacement of the new character will be relative from its origin.
Tip 3: Making Crowd Movement Naturally
When copying characters with their motions, all of them will move at the same time getting an awkward effect. To make the animation more natural, I recommend to make the motion clips a little bigger than the time set in the animation, and don’t start the sequence in the frame 0 but a little ahead, for example in the frame 100. In this way, we could move the motion clips in the timeline, avoiding the synchronization in the motion clips, resulting in a much more natural effect in the crowd.
Tip 4: Optimizing the Workflow to Check Animation in Real-time
Keep in mind that props with displacement maps, Substance materials, particles or video textures consume a lot of resources of iClone and make the project harder to handle, so I recommend putting all the characters and setting their motions, before to put those “heavy” items on the scene. It will make easier for you to check the animations in real time.
Tip 5: Motions Will Be Inherited on the Replaced Characters
There is no fixed rule to determine what level of detail you have to apply in each character. It obviously will depend on the proximity of the character to the camera, and its level of importance in the animation. The good news is that we can replace any character for another of its versions and check how it looks. The new character that replaces the previous one will inherit its motions, so we can check different levels of detail in the selected character and keep the smaller one that still looks right.
Final Render and Summary
This new feature opens a brand new world of possibilities for iClone animations, as we can use a lot of real 3D characters that can be independently animated in one single project.
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