CompuServe Thread

IPAS Comms

6 messages in this thread
#44112From: Yost GroupMay 18, 1993 3:39 PM
It's not possible to update global coordinates with an AXP in 3DSr2… only local object coordinates. We've expanded the AXP interface to handle globals, so it would be no problem in r3. You'd be able to either look at the serial port or load the coordinates via a text file. – G
#44210From: Martin BowringMay 19, 1993 2:38 PM
Can I check the terminology here. If 3DS is using a global axis then you can update the geometry relative to any point. If 3DS is using a global axis the the object can only be updated relative to the centre of the selected object. Are you saying that the AXP interface will only operate on an object relative to its local axis? If this is the case is it possible to fudge round this by creating a dummy object which have an effective local axis at the position that a global axis reference is required. Martin Bowring
#44259From: Yost GroupMay 19, 1993 11:36 PM
AXP's in 3DSr2 can only update the object based on it's local coordinate system. (Your terminology is basically correct, but the use of "global" in the second sentence is probably a typo.) We're expanding the IPAS interface to make a whole new world of possible effects, so I'd wait for R3 for something like that. I'm not sure if you could fudge it in R2 by creating a dummy, because dummy objects aren't available to AXP's at _all_. – G
#44314From: Martin BowringMay 20, 1993 2:43 PM
Sorry to be an idiot but I am still not clear on the implications of this local/global terminology. Let me give you a simple example. I have an object which is linked in the keyframer. The Child/Parent link is locked except for a single rotation plane and I have placed a pivot for the child object. If I grab the object with the mouse I can manipulate it with Object/Rotate and the object has a new orientation in the Keyframer. Have I changed the global coordinates or the local coordinates. I want an IPAS which will achieve this by calling up a dialog such as "In frame ?? rotate object ?? degrees. Is this possible. Martin
#44345From: Yost GroupMay 21, 1993 12:51 AM
You're correct in thinking that rotating an object is a local coordinate transformation. In that case, you've only changed the tranformation of the object relative to itself. You _can_ do an AXP that rotates objects in 3DSr2, AS LONG AS THERE ARE NO ROTATION KEYS APPLIED TO IT IN THE KEYFRAMER. You wouldn't actually see it rotating in the KF (because it's an AXP), but it would do it in the renderer. – G
#44534From: Martin BowringMay 24, 1993 12:44 PM
Making progress now. For one of my applications this should be sufficient. For another similar one it will be necessary to change the position in the 3D Editor or, preferably, in the Keyframer. Am I right in assuming this is a global coordinate change. Any way of using a PXP rather than an AXP. Martin Bowring