High Speed Explosion Sable Fix
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Fixes explosion damage to fast-moving Sable structures, lets explosions reach structures above the build height, and makes Create Big Cannons warheads on fast Sable craft detonate at the point of closest approach to their target.
High Speed Explosion Sable Fix
High Speed Explosion Sable Fix corrects the interaction between explosions and Sable sub-levels at high speed and at high altitude, and ensures that warheads carried by fast Sable structures detonate at the point of closest approach to their target. The mod has been tested with Create Big Cannons high-explosive shells.
Features
Explosion damage to moving structures
Explosion rays are traced through world coordinates. Whenever a ray point lies in world air, Sable queries which sub-levels have a global bounding box containing that point. It then converts the point into each such sub-level's block coordinates using the sub-level's pose, and applies explosion resistance and damage to the block found there.
Within a game tick, Sable recalculates the global bounding box of a sub-level before the physics step. The physics step then moves the sub-level and updates its pose, but the bounding box is not recalculated afterwards. For the rest of the tick, including the moment any explosion is processed, the pose describes the new position of the structure while the bounding box still describes the old one. On a moving structure, a layer of blocks along the leading edge, as deep as the distance travelled in one tick, lies inside the structure according to the pose but outside the bounding box. For ray points in that layer the query returns no sub-level, so the ray passes through as if through air: the blocks are neither damaged nor absorb any of the ray's power. The depth of the layer grows with speed, which makes fast structures practically immune to explosions that occur at their front, while blocks behind the layer are damaged normally.
This mod recalculates the global bounding box of every sub-level immediately after each physics substep, so the box and the pose always describe the same position and explosions affect moving structures correctly at any speed.
Explosions above the build height
The vanilla explosion ray march terminates as soon as a ray leaves the world bounds, including the area above the build height, so explosions have no effect on sub-levels located above that limit. This mod allows rays to continue above the build height, while the horizontal world border remains enforced.
This part is based on Sable Explosion Fix by LuveelVoom (MIT License). The same patch is included in this mod; running both mods together is harmless but redundant.
Warheads on fast structures
The game advances in discrete ticks of 1/20 of a second, and a warhead block carried by a Sable structure can detonate only on a tick. The distance a structure covers between two ticks grows linearly with its speed: at 1000 m/s it is 50 blocks. The point of closest approach to a target almost always lies between two ticks, so the explosion occurs up to half of that distance away from it, regardless of how precisely the trigger is timed.
Every on-the-spot detonation of a fuzed shell block is processed as follows:
- If the carrying structure moves fast relative to another Sable structure, the trajectory of the warhead relative to that structure is reconstructed over a window of one tick before and after the detonation.
- The trajectory is evaluated in the target's own block coordinates, so the motion of the target is taken into account.
- If the trajectory passes through the target, the blast is placed at the entry point. On a near miss (within 12 blocks by default), the blast is placed against the nearest block of the target.
- The explosion itself remains the standard shell explosion, processed through the vanilla explosion system.
Once the blast has been relocated, the carrying structure is removed together with all sub-levels attached to it. Without this step, the remaining structure would collide with the target within one tick at the full closing speed, and Sable's physics cannot resolve a collision of that depth.
Retargeting has been tested at closing speeds of up to 2000 m/s, including head-on engagements; higher speeds have not been tested.
Configuration
The warhead settings are located in the warhead section of config/highspeedexplosionfix-server.toml. The other features require no configuration.
| Setting | Default | Description |
|---|---|---|
enabled |
true |
Enables warhead retargeting. |
windowBackTicks |
1.0 |
Extent of the search backward along the relative trajectory, in ticks. |
windowForwardTicks |
1.0 |
Extent of the search forward along the relative trajectory, in ticks. |
maxMissDistance |
12.0 |
Maximum distance, in world blocks, between the trajectory and a target for the target to be engaged. |
minRelativeSpeed |
60.0 |
Relative speed, in blocks per second, below which the blast is not relocated. |
snapToHull |
true |
On a near miss, places the blast against the nearest block of the target instead of on the trajectory. |
carrierFate |
REMOVE |
REMOVE removes the carrier after a retargeted detonation. BLAST removes only the blocks the explosion would destroy if the carrier were at the blast point; this mode is not recommended at high speed. |
logDetonations |
false |
Logs every retargeted detonation, including the target, the miss distance and the relocation distance. |
Requirements
- Minecraft 1.21.1
- NeoForge 21.1.248 or newer
- Sable 2.0 or newer (required)
- Create Big Cannons 5.11 or newer (optional, required for warhead retargeting)
The mod is required on the server and optional on the client. It adds no blocks, items, recipes or commands.
Known limitations
- A collision between two Sable structures at a very high closing speed, without a preceding detonation, remains outside the scope of this mod and cannot be resolved by Sable's physics.
- The relative trajectory is approximated by a straight line over the search window; the rotation of the target within that window is not taken into account.
Credits
- The build height patch is based on Sable Explosion Fix by LuveelVoom (MIT License).
- Sable is developed by RyanHCode.
- Create Big Cannons is developed by rbasamoyai.
License
All Rights Reserved. The build height patch includes code distributed under the MIT License; the corresponding notice is provided in the LICENSE.txt file within the jar.
High Speed Explosion Sable Fix Team
