Bug: Import a specific FBX model with assimp 5.1.6/5.2.1 will freeze the app

[jianliang79]

When importing a specific FBX model with assimp 5.1.6/5.2.1, assimp will never return from Importer::ReadFile(). After some investigation I found that it seems that there is a deadloop in FBXConverter::GetRotationKeyframeList().
The FBX model which can reproduce this issue can be downloaded from the following link:
https://drive.google.com/file/d/10FKfIoY22yRsZI2wTzKyzNMT7HATY6f4/view?usp=sharing

BTW: Importing this FBX model with assimp 5.0.0 works well. This seems to be a regression of assimp 5.1.x +

[kimkulling]

Thanks for the report! I will check it!

[tippesi]

I can report the same issue with assimp 5.2.3

[kimkulling]

Hm, bad! Anyway, thanks for your testing ...

[jianliang79]

The following patch can fix this issue:

@@ -3326,9 +3326,9 @@ FBXConverter::KeyFrameListList FBXConverter::GetRotationKeyframeList(const std::
float vc = curve->GetValues().at(1);
for (size_t n = 1; n < count; n++) {
while (std::abs(vc - vp) >= 180.0f) {
- float step = std::floor(float(tc - tp) / (vc - vp) * 179.0f);
+ double step = std::floor(double(tc - tp) / std::abs(vc - vp) * 179.0f);
int64_t tnew = tp + int64_t(step);
- float vnew = vp + (vc - vp) * step / float(tc - tp);
+ float vnew = vp + (vc - vp) * float(step / (tc - tp));
if (tnew >= adj_start && tnew <= adj_stop) {
Keys->push_back(tnew);
Values->push_back(vnew);

[ghost]

I would love to see this fix get incorporated into codebase. 2 of MIXAMO animations are causing assimp to freeze.

[kimkulling]

Closed by #4554