Intel® Embree Ray Tracing Kernels
Discussion forum on the open source ray tracing kernels for fast photo-realistic rendering on Intel® CPUs.

Assert during structure build

Keymaster
New Contributor I
247 Views
Hi,
I am currently testing the new embree (1.1 beta) in my renderer. I am really impressed by the build speeds, but I keep getting one assert fail in one of my test scenes.

I reproduced it in your embree desktop application, it always happens in one fairly big scene (7M tris) with default settings (BVH4, triangle4).

It is line 81 in bvh4_builder.cpp: assert(!iter);

I've obtained permission from the author to give you the scene for debugging purposes, if you keep it confidential. If you want it, give me an email address where should it be delivered.
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6 Replies
SvenW_Intel
Moderator
247 Views
Hi, I will have a look at this. Could you please send the scene (or better a link to it) to the email address in my profile. The scene will of course be kept confidential.
Keymaster
New Contributor I
247 Views
Hi,
I unfortunately cannot find the email in your profile. Can you please post it here or contact me at keymaster( at )keymaster.cz
Simon_B_4
Beginner
247 Views
I also got this assert, but with very simple geometry. It seems to be caused by empty blocks at the start of an atomic set, the following change to common/atomic_set.h avoids the assert: typedef typename T::T Type; public: __forceinline block_iterator_unsafe (atomic_set& other) - : root(other.root), pos(0) {} + : root(other.root), pos(0) + { + while (root && 0 == root->size()) { + root = root->next; + } + } __forceinline void operator++(int) { I'm not sure if empty blocks are expected here, but thought I'd post my workaround in case it helps!
Simon_B_4
Beginner
247 Views
Actually could someone from the embree team comment on whether this change looks reasonable, or does an atomic_set with empty blocks at the start indicate some deeper issue? I am happy to provide the input data to the builder. My configuration is an AVX build using defaults. Thanks!
Keymaster
New Contributor I
247 Views
Simon B. wrote:

Actually could someone from the embree team comment on whether this change looks reasonable, or does an atomic_set with empty blocks at the start indicate some deeper issue? I am happy to provide the input data to the builder. My configuration is an AVX build using defaults. Thanks!

I got this fix directly from Swen: new atomic_set.h http://pastebin.com/WeAcdS1C
Simon_B_4
Beginner
247 Views
Keymaster wrote:
I got this fix directly from Swen: new atomic_set.h http://pastebin.com/WeAcdS1C
Thanks for that, looks equivalent to my change, I'll assume this is a valid fix then.
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