[Bf-cycles] serious bug with Curves BVH build

[Sergey Sharybin]

Hi,

It's usually good idea to have a look before asking ;)

Simplest idea to implement would be to lower the SHL used for packing,
something like [1]. Doing something like this should already help you
rendering more curve segments.

In order to fully avoid limitation here we'll need to decouple primitive
type from segment index completely. It's not fully trivial but quite doable.

[1] http://hastebin.com/erojorulen

On Fri, Nov 11, 2016 at 7:06 AM, Mohamed Sakr <3dsakr at gmail.com> wrote:

> Hi Sergey,
>
> so is there a solution? I didn't have a look yet.
>
> On Thu, Nov 10, 2016 at 10:36 PM, Sergey Sharybin <sergey.vfx at gmail.com>
> wrote:
>
>> Hi,
>>
>> In such case you're most likely hitting numeric overflow
>> in PRIMITIVE_UNPACK_SEGMENT/PRIMITIVE_PACK_SEGMENT.
>>
>> On Thu, Nov 10, 2016 at 8:45 PM, Mohamed Sakr <3dsakr at gmail.com> wrote:
>>
>>> more info:
>>> this happens when Curve got more than 32k keys (Int16), 1<<15 key points
>>> in 1 Curve.
>>> any idea? it builds bad BVH for this case.
>>>
>>> On Wed, Nov 9, 2016 at 3:01 AM, Mohamed Sakr <3dsakr at gmail.com> wrote:
>>>
>>>> Hi,
>>>>
>>>> there is a perma crash in BVH build for curves.
>>>> leaf got #DEN values.
>>>>
>>>> we got the build of 12th October, my CPU is I7 3930k.
>>>>
>>>> anybody else encountered such crashes? (all BVH types crashes, aligned
>>>> or not aligned, static/dynamic, QBVH, ..)
>>>>
>>>> this happens only with curves.
>>>>
>>>> cheers,
>>>> Mohamed Sakr
>>>>
>>>
>>>
>>> _______________________________________________
>>> Bf-cycles mailing list
>>> Bf-cycles at blender.org
>>> https://lists.blender.org/mailman/listinfo/bf-cycles
>>>
>>>
>>
>>
>> --
>> With best regards, Sergey Sharybin
>>
>> _______________________________________________
>> Bf-cycles mailing list
>> Bf-cycles at blender.org
>> https://lists.blender.org/mailman/listinfo/bf-cycles
>>
>>
>
> _______________________________________________
> Bf-cycles mailing list
> Bf-cycles at blender.org
> https://lists.blender.org/mailman/listinfo/bf-cycles
>
>


-- 
With best regards, Sergey Sharybin
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.blender.org/pipermail/bf-cycles/attachments/20161111/5529b9f5/attachment.htm