particle shaders

MikeCoker · April 8, 2022, 1:18am

I’ve noticed a weird requirement that a particle shader has to literally have certain words in the name otherwise the material gets nulled out.

github.com

cocos/cocos-engine/blob/ef013fc8c3ea5ce79cbc7d855e7b41d52b65bb1a/cocos/particle/renderer/particle-system-renderer-cpu.ts#L506

      
        
            if (!this._particleSystem) {
                return;
            }
            
            
const ps = this._particleSystem;
            const shareMaterial = ps.sharedMaterial;
            if (shareMaterial != null) {
                const effectName = shareMaterial._effectAsset._name;
                this._renderInfo!.mainTexture = shareMaterial.getProperty('mainTexture', 0);
                // reset material
                if (effectName.indexOf('particle') === -1 || effectName.indexOf('particle-gpu') !== -1) {
                    ps.setMaterial(null, 0);
                }
            }
            
            
if (ps.sharedMaterial == null && this._defaultMat == null) {
                _matInsInfo.parent = builtinResMgr.get<Material>('default-particle-material');
                _matInsInfo.owner = this._particleSystem;
                _matInsInfo.subModelIdx = 0;
                this._defaultMat = new MaterialInstance(_matInsInfo);
                _matInsInfo.parent = null!;

github.com

cocos/cocos-engine/blob/ef013fc8c3ea5ce79cbc7d855e7b41d52b65bb1a/cocos/particle/renderer/particle-system-renderer-gpu.ts#L487

      
        
            
            
public updateMaterialParams () {
                if (!this._particleSystem) {
                    return;
                }
                const ps = this._particleSystem;
                const shareMaterial = ps.sharedMaterial;
                if (shareMaterial !== null) {
                    const effectName = shareMaterial._effectAsset._name;
                    this._renderInfo!.mainTexture = shareMaterial.getProperty('mainTexture', 0);
                    if (effectName.indexOf('particle-gpu') === -1) {
                        this._renderInfo!.mainTexture = shareMaterial.getProperty('mainTexture', 0);
                        // reset material
                        this._particleSystem.setMaterial(null, 0);
                    }
                }
            
            
    if (ps.sharedMaterial == null && this._defaultMat == null) {
                    _matInsInfo.parent = builtinResMgr.get<Material>('default-particle-gpu-material');
                    _matInsInfo.owner = ps;
                    _matInsInfo.subModelIdx = 0;

This exists on the 3.6 branch where the new render updates are supposed to be, which is unfortunate. I assume you expect the name to have the word particle in it because of the parameters that are passed to the shader. Is there not a way to just make the parameters available to a shader without this hack? Maybe I’m missing something.

MikeCoker · June 20, 2022, 6:47pm

and it’s still there.

github.com

cocos/cocos-engine/blob/5bf1a24ec54c14617c4940b6824634f360a5cc17/cocos/particle/renderer/particle-system-renderer-cpu.ts#L590

      
        
            if (!this._particleSystem) {
                return;
            }
            
            
const ps = this._particleSystem;
            const shareMaterial = ps.sharedMaterial;
            if (shareMaterial != null) {
                const effectName = shareMaterial._effectAsset._name;
                this._renderInfo!.mainTexture = shareMaterial.getProperty('mainTexture', 0);
                // reset material
                if (effectName.indexOf('particle') === -1 || effectName.indexOf('particle-gpu') !== -1) {
                    ps.setMaterial(null, 0);
                }
            }
            
            
if (ps.sharedMaterial == null && this._defaultMat == null) {
                _matInsInfo.parent = builtinResMgr.get<Material>('default-particle-material');
                _matInsInfo.owner = this._particleSystem;
                _matInsInfo.subModelIdx = 0;
                this._defaultMat = new MaterialInstance(_matInsInfo);
                _matInsInfo.parent = null!;

AndyTian · June 22, 2022, 6:23am

hi, thanks for the feedback, obviously this is not the right way to go. we have lined up a particle system refactor plan but havent got time to make much progress yet, hopefully in 3.7 we can have a much more orgnized particle system.