HM memory run-away

[sdanaher]

The second issue we're experiencing was due to an object with multiple HN causing a run on system memory. Octane Log reports 15GB used, but on 'Updating....' C4d Memory usage climbed to over 70GB and system ran out of RAM. We reduced all HN render subs to 1 but it still occurred. The objects were the Dosch cars from the built-in c4d presets (they are not very efficiently built but still...)

[aoktar]

Where it happened? Live Viewer or Picture Viewer? What's render settings?

[sdanaher]

both LV and PV, PV much worse though.

Render settings, do you mean octane settings or render (it was 60x60cm @ 300dpi).

Are there any known issues with HN? There were 8 objects and each had about 6 HNs in them, and lots of hierarchical grouping with nulls (it was a Dosch car model). I notice there was 1 nested HN in the hierarchy so it was getting double the subdivs, though still only level 1. Tried octane subdivs but still had memory issues.

[aoktar]

Try to put object tag on each object. How much polygon do you have on those?

[sdanaher]

The cars are all in Presets > Visualize > 3D Objects > Vehicles (Hot Hatch, Sedan and SUV byt Dosch) if you'd like to take a look?

[aoktar]

The cars are all in Presets > Visualize > 3D Objects > Vehicles (Hot Hatch, Sedan and SUV byt Dosch) if you'd like to take a look?

Ok! I don't have these on my lib. Try to put object tag on top every cars to make sure all movable. Try octane subdivision from tag and don't go high on division values. There's much things to do else of those.

[sdanaher]

I've fixed it by completely reorganising the model structure and using instancing where possible (makes things difficult when you need to have multiple of the same car but different colours).

But really I need to understand what the problem was - is having many HNs in a scene an issue, or was it the complex hierarchy inside the HNs? (I know cinema is not good with large numbers of objects, better to combine polys into single object).

Is it a bug that Octane reports using 25GB (before I optimised) but Cinema runs out of RAM by using 70+GB during the Updating phase.

Why this disparity?

[aoktar]

Propably all objects are static and goes to one memory buffer for sending to renderer. That's why i say to use object tags on top to make all movable, so it will seperate buffers. It's not a bug, just current system. I can say exact words if you post your scene.

[sdanaher]

Ah, thanks for the explanation. That is a big help for troubleshooting going forwards. I will retest when I have some time.