CompuServe Thread

bug in DOTS texture ????

4 messages in this thread
#37445From: John LemoineMar 28, 1992 11:41 AM
Hi All Has anybody noticed problems with the DOTS texture supplied with Imagine 2.0. I have found that it does not work the same as the one that was with 1.1. I have a 800×600 plane and has a DOT texture map, with a spacing of 60, and a dot size of 10. When Rendered the dots don't show up unless I increase the dot size to about 27, then they will show up. It seems from my experimenting that in 2.0 the dots must be about 1/3 or bigger in relation to dot spacing or they disappear. This texture map worked fine in 1.1 at any dot size so it would appear to be a bug in the DOT texture. As a result several of my pictures that were work in progress, have to be put on hold until I figure out what is wrong or else I have to go back to 1.1 to finish them. (I prefer 2.0, thats why I paid my money). Can anyone confirm this! / So much Great Amiga Software, so little Time !! \/ John Lemoine via Whap! 75320,143 Edmonton, Alberta, Canada
#37490From: Charles BlaquiereMar 29, 1992 5:21 PM
John, I have a hunch as to what may be wrong. Disclaimer: everything in this message is pure theory, based on my perception of how Imagine works! Bricks are welcome. The Dots texture is three-dimensional, basically a 3-D grid of spheres. If a vertical plane passes through the exact center of the spheres, all the dots will be the same size, the size specified in the texture parameter screen. Now say you move the plane towards you (i.e. perpendicular to its surface). The plane still intersects the same spheres, but they'll all appear smaller because they're "sliced" closer to their surface. If you move the plane a bit more than the dots' radius, they'll seem to disappear. At this point, increase the dot size in the texture. Presto, the dots will reappear, because the plane now intersects part of the new, larger dots. Of course, they'll be smaller, since a smaller part of the dot intersects the plane, compared to the original placement, where the plane intersected each dot through its center. Why, you may have to increase dot size by as much as 3 to 1 to get the same result with the offset plane. :^) Now realize that this translation could be the result of moving the plane, or moving the texture axis. :^D Of course, we all know Imagine 2.0 has a handy-dandy new default placement for texture axes. B^D Maybe there is a connetion here? I suggest you go back and make sure your texture axes are where you think they are. Blaq!
#37528From: John LemoineMar 30, 1992 11:25 PM
Charles Blaquiere I thought that the dots texture was a map of disks, not 3d-Spheres. In any event I have WASTED another evening trying to get DOTS to work. I have placed a DOTS texture on a plane 800×600 in dimension with the texture axis x=0 y=0 z=+5, this does work o.k. if you use the default size settings when you load the texture but does'nt work at almost any other settings. In particular I want to get a spacing of 60 and a dot size of 10, seems simple enough and it did work fine in Imagine 1.1, but does not now with version 2.0. Grrr!! every time I start to get somewhere with Imagine, something stupid like this rises up and kicks me down and makes me waste dozens of hours and CPU time. It's a good thing I don't have to make a living with this program. / So much Great Amiga Software, so little Time !! \/ John Lemoine via Whap! 75320,143 Edmonton, Alberta, Canada
#37542From: Bruce PatekMar 31, 1992 8:19 AM
John, I received Steve Whorley's "Understanding Imagine 2.0" recently and he describes the Dots texture as actually being spheres in a 3D grid. So the dot spacing, dot radius and axis size will be critical, especially with an irregular object. With even a plane, everything would have to be right to make sure the plane is cutting through each dot (sphere) enough to see a good slice of the dot. This is why he says with an irregular object, your dots will be different sizes. I'm still experimenting myself (For 3 years!), but I'm having fun. BP. – via Whap!