Strange "Linepick" situation
Blitz3D Forums/Blitz3D Programming/Strange "Linepick" situation
| ||
| LinePick(EntityX(gb),EntityY(gb)+h,EntityZ(gb),EntityX(gb),EntityY(gb),EntityZ(gb)+2115) The above LinePickcommand in my app finds an object which stands between the Entity "gb" and its target.The +h is just variable in a loop that checks different heights along the line. Now;I got the distance from "gb" to the target two ways. From the relative position of the object posZ and "gb" posZ and the Blitz distance command.That result was 250. I did bioth ways just for a double check. Notice the +2115 in the LinePick command.If I make that number any less the LinePick does not find the object. Is this as it should be and if it is - why and how is it computed.Otherwise -what the heck??????? |
| ||
| Have you applied scaling to the entity? If so you must scale the line pick also. |
| ||
| Yes,I scaled the object 2.5. That still does not relate 2115 to 250 in any way. Nor does scaling seem to effect the distance. Are you sure that is relevant? |
| ||
| You are using linepick incorrectly: Your first 3 parameters are correct -the position you wish to linepick from. The next 3 parameters should be the components of the vector from your starting position to your ending position. Assuming your target point is at coordinates "TargetX#, TargetY# and TargetZ#" then do this instead: linepick entityx(gb),entityy(gb)+h,entityz(gb),targetx-entityx(gb),h+targety-entityy(gb),targetz-entityz(gb) |
| ||
| Matty - I really do not have a target. My intent is to go on for infinity (Kind of). Basically what I am doing is a vector to nothing. I just wonder if the spot of the hit cannon be measured in this manner. |
| ||
| If it's any help, my linepick from the sky to the ground messed up until I realised that I had to use EntityPickMode on the ground. (Doh!) EntityType Ground\hent,TYPE_TERRAIN EntityPickMode Ground\hent,2 - or whatever. |
| ||
| Jack - what do you mean by a 'vector to nothing'. 'My intent id to go on for infinity' - what direction though (a vector is not just magnitude but also directional). I didn't quite understand what you meant by "I just wonder if the spot of the hit cannon be measured in this manner". |
| ||
| Use EntityPick() instead. |
| ||
| Matty - it is in the "Z" direction only. Jeremy - Why? .The lLinePick is fine otherwise. |
| ||
| Jack - Local Z Direction or Global Z Direction? (ie character or object's forwards direction or the world's forwards direction) If you want to check for an object using linepick in the 'local z direction' then you will need to use the TformVector commands to transform the entity's space to the world space. As an example, if I were to have a character that I wanted to test for an object that is directly in front of it (local space) then I would do this: LocalX#=0 LocalY#=0 LocalZ#=some number for how far in front you wish to check.. TFormVector LocalX,LocalY,LocalZ,CharacterEntity,0 ;the above line takes a vector and transforms it from your character's local space to the world space (or global coordinates) objectihit=linepick EntityX(CharacterEntity),EntityY(CharacterEntity),EntityZ(CharacterEntity),TFormedX(),TFormedY(),TFormedZ() ;this performs a linepick directly forwards from the character's point of view. ;put the rest of your code here as normal... Note though that (in my experience) linepicks are often slow and wherever you can get away without them the better |
| ||
| John - Thanks.I made sure I did this a while back. Matty - At this point I am not sure that this is a problem since I have not rotated the "character" and the move commands all work as expected.IE - the Z direction is straight into the distance.BUT - I'm glad you gave me this info since that will not always be the case and I never thought of setting the linepick this way.I figured on having to do some angle stuff when I rotate the "character" I will check this as the "character" is pointed now.Since I will always want the linepick from the direction the "character" is pointed I guess I can set this once and forget it for the remainder of the time the object is moving. By the way - I'm not too worried about the time factor since this will only fire once - before movement starts. I cannot use EntityPick" because I need to get the SURFACE hit and not just the OBJECT. Thanks for the input. |
   |