It is recommended to use the latest version of FusionFix, as some special effects require FusionFix to work
It is recommended to be used in combination with any road texture module This road texture is recommended
https://www.nexusmods.com/gta4/mods/643
Other road surface textures do not guarantee this effect

Installation method：
Place the files in the "Main Directory" into the gta4 game directory for replacement
Replace the files within "OpenIV Replacement" with OpenIV. This includes various high-definition textures such as vehicle stains, but it's not necessary

Open "GTAIV.EFLC.FusionFix.ini" of FusionFix and find the following lines
OverrideCascadeRanges = 0.3                     // increases shadow view distance and improves quality at lower settings
ShadowSoftnessBlendRange = 0.3                // size of the cascade blur blending region | [0.0; 1.0]

Replace with
OverrideCascadeRanges = 1                     // increases shadow view distance and improves quality at lower settings
ShadowSoftnessBlendRange = 1                // size of the cascade blur blending region | [0.0; 1.0]

Look again
[SHADOWFILTERCHSS]                            // CHSS / PCSS
ShadowSoftness = 1.5                          // controls minimum shadow blur
ShadowBias = 5.0                              // controls shadow bias, adjust according to minimum softness
MaxSoftness = 10.0                            // controls maximum shadow blur
LightSize = 500.0                             // how quickly the maximum blur is reached
ExtraBias = 2.0                               // extra bias for large penumbras

Replace with
[SHADOWFILTERCHSS]                            // CHSS / PCSS
ShadowSoftness = 0.4                          // controls minimum shadow blur  
                                                   （Increase this value when jagged shadows appear）
ShadowBias = 2.0                              // controls shadow bias, adjust according to minimum softness
MaxSoftness = 27.0                            // controls maximum shadow blur
LightSize = 700.0                             // how quickly the maximum blur is reached
ExtraBias = 1                               // extra bias for large penumbras

Find it again
[SUNSHAFTS]
SSType = 2
SSSamples = 30
SSWeight = 1.5
SSDensity = 0.95
SSExposure = 0.01
SSDecay = 0.975
SSSunSize = 0.5
SSPow = 1
SSDepth = 2
SSPower = 1.5

Replace with
[SUNSHAFTS]
SSType = 2
SSSamples = 30
SSWeight = 1.5
SSDensity = 0.95
SSExposure = 0.01
SSDecay = 0.975
SSSunSize = 0.5
SSPow = 1
SSDepth = 2
SSPower = 2.8

Finally, enter the game and adjust the corresponding options according to the picture in "FusionFix Settings"

Completed!