Yes, I did what you suggested. When I debugged the code, I noticed that the 'vehicle.json' file could not be read, and the system was returning a null value. I checked the location and content of all other files referenced in the 'vehicle.json' file and could not see any issues.
Initially, I thought the GetDataFile function wasn't returning the correct file directory. However, I encountered the same problem even when I bypassed that function and manually hard-coded the direct path into the code. To check if the problem was with the JSON files I created, I tried using the standard HMMWV JSON files that come with the Chrono installation, but the issue persisted. 11 Kasım 2025 Salı tarihinde saat 12:23:06 UTC+3 itibarıyla Radu Serban şunları yazdı: > This kind of issues are difficult to debug without a full working example. > > My suspicion is that some JSON file is not found as expected. Note that > the JSON files referenced from the top-level vehicle JSON file must be > provided relative to the vehicle data directory. > > > > But all of this is not that relevant. Such an issue can **very** easily > be identified by building the code in **Debug** mode and stepping through > it with a debugger. Step through each subsystem constructor and ensure > that the JSON file it attempts to use is what you expect. Have you done > that? > > > > Radu > > > > *From:* [email protected] <[email protected]> *On > Behalf Of *Emrullah Cebeci > *Sent:* Monday, 10 November 2025 16:40 > *To:* ProjectChrono <[email protected]> > *Subject:* [chrono] Project Chrono 0xC0000005 Crash - Access violation on > vehicle.Initialize() (Custom JSON Loading Issue) > > > > Hello, I am trying to load a custom vehicle in Project Chrono using JSON > files, but I am receiving a 0xC0000005: Access violation (*Null Pointer*) > error that I cannot solve. > > The program always crashes when it reaches the vehicle.Initialize(...) > line. This indicates that the WheeledVehicle constructor failed, and the > vehicle object is being created as a null pointer (nullptr). > > I believe the file references in my JSON files and my main.cpp code are > correct. My JSON file structure is as follows: > C:/Projects/vehicle_project/data/temp/vehicle/vehicle.json > > Here is the relevant section of my main.cpp: > > #include "chrono_vehicle/ChVehicleModelData.h" > // ... other includes ... > > using namespace chrono; > using namespace chrono::vehicle; > > int main() { > > // SetDataPath points to the 'data' directory from the file tree above > const std::string vehicle_data_path = > "C:/Projects/vehicle_project/data"; > chrono::vehicle::SetDataPath(vehicle_data_path); > > // The vehicle JSON is called relative to the 'data' directory > const std::string vehfile = "temp/vehicle/Vehicle.json"; > WheeledVehicle vehicle(vehfile, ChContactMethod::SMC, false, false); > > // THE ERROR OCCURS ON THIS EXACT LINE > vehicle.Initialize(ChCoordsys<>(ChVector3d(0, 0, 0.6), > QuatFromAngleZ(0))); > > // ... (rest of the code) > } > > I would greatly appreciate it if you could tell me what is causing this > problem and how to solve it. Thank you. > > > > > > -- > You received this message because you are subscribed to the Google Groups > "ProjectChrono" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/d/msgid/projectchrono/4726cd2f-6b05-4bb9-8f99-66708abb54d5n%40googlegroups.com > > <https://urldefense.com/v3/__https:/groups.google.com/d/msgid/projectchrono/4726cd2f-6b05-4bb9-8f99-66708abb54d5n*40googlegroups.com?utm_medium=email&utm_source=footer__;JQ!!Mak6IKo!OuIEFyot2_gsXLCOsY0-A5jBZ-BnQCkPhaBDc-1X1EmuNBQMVr5N-wUdyLOFqpvXL7jK3LzSY-u-0jkXOC812P0s$> > . > -- You received this message because you are subscribed to the Google Groups "ProjectChrono" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/projectchrono/429ba68e-fd53-480b-b4f7-ab6fb7faee38n%40googlegroups.com.
