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IPO curves for Alpha

Posted: Wed Dec 15, 2004 7:13 pm
by mataii
hello everybody., well i have a question about alpha channel in the ipo curve editor.. I-m trying to animate tue alpha from a plane with an animated texture... i want to make the plane get invisible at certain frame., but I cant activate the alpha.,.., I have never used so I cant figure how to do it, and if somebody know that, I hope they told me :P

many thanks :)

Posted: Wed Dec 15, 2004 7:19 pm
by kirpre
Maybe this isn't what you're looking for, but this is how I keyframed an animation with an object that faded in. You hit 'I' to create a keyframe just like you would for an object, but make sure the mouse is over the materials button area, not the 3D area. If you do this, you will get a different set of keyframing options, one of which is Alpha. Hope this helps.

Posted: Wed Dec 15, 2004 7:38 pm
by mataii
kirpre wrote:Maybe this isn't what you're looking for, but this is how I keyframed an animation with an object that faded in. You hit 'I' to create a keyframe just like you would for an object, but make sure the mouse is over the materials button area, not the 3D area. If you do this, you will get a different set of keyframing options, one of which is Alpha. Hope this helps.
thanks kirpre :) but I think it only works for the render, not to be used in the engine,. we can only use materials but only to use the DYN options in the engine :(

Posted: Wed Dec 22, 2004 5:25 pm
by joshuaseaver
It does work, but it isn't very intuitive.
In order to create transparency without using a texture map, you will need to add an IPO curve to the object.
This is helpful if you want to animate the transparency (or color) over time.

Select your object and open the IPO Curve Editor. LMB click on the ColA attribute. This is the objects Color attribute that specifically controls its alpha value.
Hold down CTRL and LMB click on the grid at O, O. If you need to place it precisely, press NKEY to bring up the numeric editor and change the values manually.
A value of 0 means transparent, while a value of 1 means opaque. The value can be set anywhere between those values, and can be animated by setting more IPO keyframes.

Now go to the Texture face panel and activate ObColor. This tells the game engine to use the objects color information. You may need to set values (keyframes) for the ColR, ColG, and ColB attributes if the object isn't the color you want it.

Posted: Thu Dec 30, 2004 10:36 pm
by mataii
Thanks a lot joshuaseaver! :) It helps a lot thanks again :wink:


:P

Posted: Sun Jan 16, 2005 2:07 pm
by arangel
Thanks, Joshua!