>Correct. You have just described the correct function of the DOT3 >algorithm. Remember that DOT3 takes two vectors as input to generate a >scalar value as output. One vector comes from the bump map, the other >vector has to come from somewhere. That other vector describes what the >light direction is. That other vector has to come from somewhere. If you >look at the combine equations, there is only one unused input color >value. There are two places that the combine mode allows you to provide >that color from: A constant color or the previous stage of the texture >pipeline. Either way, that "color" value is actually interpreted as the >light vector that is shining on the surface. A constant color is easy to >understand. If you are taking the color from the previous stage of the >pipeline then it really doesn't matter what that color is, it is >interpreted as a vector. So, if you have used the bump map as the first >stage in the pipeline, then the underlying color is actually the object >color - ie per-vertex coloring represents the incident light, not a >color. That's why you are loosing the material color. As for the >greyscale output, that's because the output of the bump map is a scalar, >and is therefore applied to all color components equally, thus only >allowing grey values.
Okay. so if i understood you correctly, there is t least one thing i have to do with vertex colors in order to have correct bump direction: set it so the resulting normals indicate the real direction of light, and not a static one. I remarked that whatever the rotation of my object, the bump always seemed to be the same. Then, it seems that - i can't apply a mapping under the bump, until i make it in a second pass. - i can't apply anything over the bump, as multitexturing is not working when using combine modes in current implementation. (Last time i had the j3d team, it was to be implemented for 1.4...) So, i"ve been digging to get control over multiple passes, and it seems that we have no control over this. Is there a trick or something i missed? thanks a lot for the insight. That helped me a lot. =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff JAVA3D-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
