https://community.intel.com/t5/Intel-Embree-Ray-Tracing-Kernels/rtcSetTransform-instance-positioning/m-p/1056682#M513 <P>Hi,</P> <P>How do the positioning of instances exactly work? I know that rtcSetTransform convert from local to world space, but positioning seems very weird. Let me explain what I do and what it does...</P> <P>I create a cube at&nbsp;origin (0,0,0) and instantiate it at (10,0,0) all works well. If I rotate the instance, all works well.</P> <P>Now, create the cube at origin (100,50,-300) and instantiate it at (10,0,0) (which I assume it is the offset from the master)&nbsp;again all works well, the instance is positioned at origin+(10,0,0). BUT, if I rotate the instance, it is no longer positioned at origin+(10,0,0), it is way out some place not even close to where it should be!</P> <P>The documentation doesn't explain anything about this. Can anyone please explain to me what I'm doing wrong?</P> <P>Thanks,</P> <P>-Al</P> Mon, 07 Jul 2014 19:46:12 GMT Al_N_ 2014-07-07T19:46:12Z https://community.intel.com/t5/Intel-Embree-Ray-Tracing-Kernels/rtcSetTransform-instance-positioning/m-p/1056682#M513 <P>Hi,</P> <P>How do the positioning of instances exactly work? I know that rtcSetTransform convert from local to world space, but positioning seems very weird. Let me explain what I do and what it does...</P> <P>I create a cube at&nbsp;origin (0,0,0) and instantiate it at (10,0,0) all works well. If I rotate the instance, all works well.</P> <P>Now, create the cube at origin (100,50,-300) and instantiate it at (10,0,0) (which I assume it is the offset from the master)&nbsp;again all works well, the instance is positioned at origin+(10,0,0). BUT, if I rotate the instance, it is no longer positioned at origin+(10,0,0), it is way out some place not even close to where it should be!</P> <P>The documentation doesn't explain anything about this. Can anyone please explain to me what I'm doing wrong?</P> <P>Thanks,</P> <P>-Al</P> Mon, 07 Jul 2014 19:46:12 GMT https://community.intel.com/t5/Intel-Embree-Ray-Tracing-Kernels/rtcSetTransform-instance-positioning/m-p/1056682#M513 Al_N_ 2014-07-07T19:46:12Z