Hi, I tried to use “Bvh” for Group Node for days but I failed.
My Optix hierarchy it is created as follow: I have three layers of Group Objects: MainNode, TOptixGroupObject(GLItem) and TOptixGroupObject(GLMesh).
Under the TOptixGroupObject(GLMesh) node, the last Group Objects, I have one Transform Object then a GeometryGroup, then a GeometryInstance finally a Geometry Object (classical structure).
I’ve created Accelerators for Group Objects and GeometryGroup Objects.
The “Bvh” works fine for GeometryGroup Objects (trinagle meshes) but not for Group Objects. The only way to obtain a valid image is to use “NoAccel” for Group Objects (still using “Bvh” for GeometryGroup Objects).
If I use “Bvh” acceleration type for Group Objects, I get only black boxes (the exact size of the bounding boxes of the GeometryGroup Objects)
See the images below.
P.S. I’m using Optix 3.5.1 32 bit, Cuda 6.0 (or 5.5) with a GTX 460M card
I don’t set “refine” and “refit” values for BVH traversal algorithm (using default value) maybe in the afternoon (I’m in Italy) I’ll do some test on this…
[UPDATE] No acceleration type different from “NoAccel” works, every acceleration different from “NoAccel” render only black bounding boxes…
I’ve seen that in you code that you set the accelerators only to GeometryGroups, in my case I use them for GeometryGroups and for “simple” Groups (no geometry only tree structure).
In my case GeometryGroups work (any accelerator) but Groups don’t (black BBox) maybe its an Optix bug?
I’ve seen, in your code, that you set the accelerators only to GeometryGroups, in my case I use them for GeometryGroups and for “simple” Groups (no geometry only tree structure).
In my case GeometryGroups work (any accelerator) but Groups don’t (black BBox) maybe its an Optix bug?
The problem was due to “RT_EXCEPTION_STACK_OVERFLOW”.
I’ve made some test to get the minimal configuration that cause the Problem (exception if I use an acceleration structure):
If I use just one top Group object with GeometryGroups children it works (“bvh” accel on for Group Accelerator)
If I use one top Group object with Tranform Objects children each with its GeometryGroup child, it doesn’t work (with “bvh” I get the exception, with “NoAccel” works fine)
If I use one top Group object with Groups Objects children each with its GeometryGroup child, it doesn’t work (with “bvh” I get the exception, with “NoAccel” works fine)
Somewhat it is connected with the depth of the Tree.