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IDProjectCategoryView StatusLast Update
0005138The Dark ModCodingpublic30.11.2020 12:34
Reporterstgatilov Assigned Tostgatilov  
Status resolvedResolutionfixed 
Target VersionTDM 2.09Fixed in VersionTDM 2.09 
Summary0005138: Refactor particle systems code
DescriptionCurrently particle systems code is split across files:
  ParticleDecl.cpp --- some common code
  tr_deform.cpp --- emitting surfaces only
  Model_prt.cpp --- particle models only
  ParticleCollisionStatic.cpp --- offline tool for computing collisions (new)
Now the problem is: I have to duplicate some code in ParticleCollisionStatic.cpp.
To support "mapLayout linear" I will have to duplicate much more unless some refactoring happens.

The idea is to factor all the common code into a new file.
ParticleDecl.cpp will be only for reading/parsing decl files, all the particle-modelling code will be called from the new file.
The code for emitting particles from tr_deform.cpp and Model_prt.cpp will be moved to new file too. That's the main thing: allow to reuse emitting logic of both cases.

Things to keep in mind during refactoring:
1) Split particle origin computation into several pieces, in order to fix bounds computation (0005136).
2) Use structs and functions instead of classes and methods. This way it would be possible to compile the same code with GLSL in future.


related to 0004957 resolvedstgatilov Snow and rain particles stopping on brushes 
related to 0003161 resolvedSteveL Dousing a fireplace causes smoke to bounce 
related to 0004132 resolvedSteveL Weather particle distribution should be more random 
related to 0005136 resolvedstgatilov Wrong bounds of particle system 
related to 0005437 assignedstgatilov Particles: static collision with "linear" mapLayout 
related to 0002642 assignedstgatilov Add multiple particles to func_emitter 




22.11.2020 17:06

developer   ~0013011

I added 0002642 to this issue as it relates to the particle system design.

That said, I also did this to highlight the fact that the "SEED system" is basically like a large scale particle emitter and would
benefit from the same things that a particle system would ( geometry instancing, transform feedback, etc).

There is probably a decent amount of code duplication between SEED and the particle system and the render backend
with the whole "ModelGenerator.cpp code in the Game section of the project.


30.11.2020 10:47

administrator   ~0013053

Forum post:


30.11.2020 12:18

administrator   ~0013056

Well, the refactoring is finished.
It started with preliminary commits 9008-9010, followed by main changes in 9011-9018.

Now almost everything is moved to ParticleSystem.[h/cpp].
Note that ParticleSystem_[def/decl].h are considered to be parts of these files.
These parts has some basic GLSL compatibility, making it possible to run this code on GPU (not sure if it is worth it though).

The code in C-style, passing structs with raw around.
All the functions are named idParticle_XxxYyyZzz and never access any global state: all inputs and outputs are explicitly marked.
As the result of refactoring, the duplicate code is deduplicated =)
Also, some parts of the computation are split into subparts for better resuse.

Here are some notable changes:
1) Random seed for each particle is now computed by hash function of its index and other quantitites, instead of "stepping random" paradigm (see 0003161).
2) Randomizer for particle deform system is now computed from model name/surface index instead of its coordinates (see 0004132).
3) Bounding boxes are fixed (see 0005136).
4) Added check for image size mismatch.

Issue History

Date Modified Username Field Change
01.02.2020 05:35 stgatilov New Issue
01.02.2020 05:35 stgatilov Status new => assigned
01.02.2020 05:35 stgatilov Assigned To => stgatilov
01.02.2020 05:35 stgatilov Tag Attached: particle
01.02.2020 05:36 stgatilov Relationship added related to 0004957
01.02.2020 05:36 stgatilov Relationship added related to 0005136
22.02.2020 13:47 stgatilov Target Version TDM 2.08 =>
21.03.2020 17:40 stgatilov Product Version TDM 2.07 => TDM 2.09
21.03.2020 17:42 stgatilov Product Version TDM 2.09 =>
21.03.2020 17:42 stgatilov Target Version => TDM 2.09
15.11.2020 17:38 stgatilov Relationship added related to 0003161
22.11.2020 10:52 stgatilov Relationship added related to 0004132
22.11.2020 12:49 nbohr1more Relationship added parent of 0002642
22.11.2020 17:06 nbohr1more Note Added: 0013011
30.11.2020 10:07 stgatilov Relationship added related to 0005437
30.11.2020 10:47 stgatilov Note Added: 0013053
30.11.2020 12:18 stgatilov Note Added: 0013056
30.11.2020 12:34 stgatilov Relationship deleted parent of 0002642
30.11.2020 12:34 stgatilov Relationship added related to 0002642
30.11.2020 12:34 stgatilov Status assigned => resolved
30.11.2020 12:34 stgatilov Resolution open => fixed
30.11.2020 12:34 stgatilov Fixed in Version => TDM 2.09