RailClone Render Problem

[Mike Truly]

Hi Carlos,


MAX2010_64 & currently using RCP 1.3

I've got something very weird happening.  I have a project that I have been using RCP on and it has been working well and rendering fine for a long time.

Then yesterday, I go to render a 900 frame sequence (that I have rendered many times before without problem) and I notice that the queue manager is showing that a single frame in the sequence has failed to render and different render slaves are attempting to render this one frame and all are failing.

So I then used the main workstation to try and render this one frame... and it fails.  It will render all the other frames in the sequence without problems but fails on frame 839.  It seems to be related to the fact that the camera is set to ortho projection.  With the camera set to ortho projection and a RailClone object showing...  the render on this one frame fails.  If the camera is set to ortho projection and a RailClone object is NOT showing (and a regular teapot is)... the render is successful.  If the camera is NOT set to ortho and a RailClone object is showing... the render is successful.

So it seems to be related to this one frame, using ortho on the camera, and a RCP object showing.  I've attached a zipfile containing a test scene.  Go to frame 839 and try to render the camera with ortho ON.

Again, all these frames were rendering successfully for quite awhile but now this one frame refuses.  I will try to install the newer version of RCP.

Thanks for any ideas!

[Mike Truly]

OK, I tried installing the latest version of RCP (v 1.4.2) but the problem still happens when trying to render this one frame.

[iToo]

Hi Mike,

This is a interesting issue. Reproducing the problem here, i got a crash rendering frame 839 (non ortho)... but even converting RC to an editable mesh ! . It seems a bug of the scanline renderer, by some reason it crashes (or in your case it fails using ortho) with that specific geometry and view.

A very rare bug, but it would happen with a certain combination of numbers in the internal render algorithm. May be caused by a vertex, a face or whatever else... really it is impossible to know. I tried to render this frame using Mental Ray, and as expected, it doesn't show this problem.

Anyway, just moving the camera a bit seems to solve the problem.

[Mike Truly]

Thanks for taking a look at this Carlos.

On my system, changing the camera to non-ortho will render f839 fine... but I need the ortho camera.  If the camera is in ortho mode and a RCP object is visible... it fails.  If the camera is in ortho mode and a RCP object is not visible... it renders fine.  So for my current tests, it fails whenever the RCP object is visible and the camera is in ortho on this single frame  (weird I know).

I also discovered that moving the camera target slightly would make the render successful with the RCP object visible... so I am going to try to use this method to fix this one frame.

Thanks again.