CompuServe Thread

Hi John, Dave Marks has done a lot of work with z-buffering. Perhaps he will jump in here. I would be very interested in taking a look at your routine when you have somthing working (even in the alpha stages). Lee

Hi John, Hi John, << ..but have not heard anything yet..>> Please see msg #186447. I answered you on Friday Aug 18tht. 8:42:24 am. 🙁 << .. routine to access the objects mesh min and max X,Y,Z values. However, the values appear to be in object local co-ordinates and I need the world co-ordinate XYZ values (as in the ASC file). >> If you have R4, check out the following 2 keyscripts written by Tom Hudson which offers insights into your problem. ;———————————————————– ; PIVOT.K3D ; Pivot Point Alteration Demo (Object Space Version) ; 3DStudio R4 ; 940708 ; Tom Hudson ; ; This program demonstrates how to alter the pivot point of an object. ; ; Pivot points are stored in the local coordinate system of the object. The ; pivot point of an object is the alignment point used for the location of ; the position keys. If we alter the pivot point, the position keys must ; also be adjusted accordingly, or else the objects will shift position after ; the pivot is altered. In order to avoid a shift, it is necessary to ; transform the old and new pivot points through the object's transformation ; matrix. This gives the new pivot point's offset from the old pivot point ; in world coordinates, where X is left/right, Y is front/back and Z is ; bottom/top. Once this value is calculated, the position keys are adjusted ; accordingly. ; ; See PIVOT2.K3D for a demonstration of setting the pivot point to a world ; coordinate. << 1. The rectange is not consistant in a X,Y,Z ratio How is this calculated and can I reproduce it ??? >> File Info for CAMERA.ZIP Section: Software Dev. Kits Contributor: 73172,1351 Size: 7511 Submitted: 5/19/94 Type: Binary Accesses: 92 Title: Thread outlining a test of 3ds FOV Keys: 3DS FOV CAMERA A thread primarily between John K. Jordon and Michael E. Bartlett and their scientific experiments to test the accuracy of 3DS' cameras FOV. << 2. The direction of the camera to target is variable. Is there a way for me to detect in which direction the camera is facing ie what axis the FOV is related to. >> There's a script in Inside 3DS for Release 4 that may help you…. ' '———————————————————– ' CAMTRACK.K3D ' Keeping Objects Perpendicular to a Camera's Position ' An "Inside 3D Studio" utility ' By: Jonas Ruikis ' ' CAMTRACK rotates a selection of objects about their pivot point (of course) ' so their first face is prependicular to a selected Camera's position. ' Axes may be locked for the objects. ' Either the camera and/or the objects may be in motion. ' Respects the current Time Segment jonas[adesk]

Hi John, << I have written a IPAS routine to access the objects mesh min and max X,Y,Z values. However, the values appear to be in object local co-ordinates and I need the world co-ordinate XYZ values (as in the ASC file). >> In addition to my previous post, the following file demonstrates the use of Local and World coordinate bounding boxes. File Info for ALIGN.ZIP Section: Scripts Contributor: 73172,1351 Size: 7825 Submitted: 2/17/95 Type: Binary Accesses: 226 Title: Planet Studio: Align script Keys: PLANET STUDIO ALIGN K3D SCRIPT PHILLIP MILLER Align script for Planet Studio. Align one or more objects in the keyframer. ; ;Alignment by Object Bounding Box Extents! ;by Phillip Miller jonas[adesk]

Before I answer, let me qualify this with a statement that I have not done IPAS programming, and my knowledge of the mathematics involved is limited, but rapidly catching up. I HAVE done some script programming so I CAN offer some ideas that may help… >> I need the world co-ordinate XYZ values (as in the ASC file). << The Script Extensions (TSE) offer a parameter that allows you to call the Bounding Box in either local or world coords. If the IPAS API doesn't allow that, you will have to use a combination of the local axis (in world coords) together with the transformation matrix to determine the BBox coords. >> 1. The rectange is not consistant in a X,Y,Z ratio << I believe the camera aspect ratio is determined by the render settings. Someone with more IPAS knowledge will have to fill you in with details on actual calculation of the camera cone… >> Is there a way for me to detect in which direction the camera is facing << In TSE a camera structure has separate coords for camera and target. It should be a fairly basic calculation between two points to determine the camera-target vector. >> …seez.ixp and we are finding color in the output file. Any ideas ? << If you need pure grey-scale, try turning off your gamma correction. I'm guessing here, but possibly the gamma correction curves are slightly shifting the colors. FWIW, the z-buffer is VERY easy to access via TSE (and I'm guessing IPAS as well). Given a z-buffer value, it is relatively easy to generate any color spectrum you prefer. It's all a matter of percentages and basic math. Hope this helps. – Dave