Simple question about materials; not sure how to search for it

Qwiggalo

I'm making simple rain for my level, that's not really important, but I have a panning texture sample, it's great, I'm happy with how it is. My material is translucent and I want to add an opacity mask onto the entire material as a gradient ramp from 0 to 1 in V, how would this be done?

The reason for this is so when you look up the end of the planes that the rain is panning on isn't easy to see. I've made it easier to see in this image.

Visceral

Make a gradiant in photoshop, multiply that with the current mask and plug into Opacity?

Qwiggalo

Is there a way to make a gradient without making a texture? That's what was getting me stuck, something as simple as that seems like a waste of resources to import a texture for it.

passerby

Qwiggalo wrote: »

Is there a way to make a gradient without making a texture? That's what was getting me stuck, something as simple as that seems like a waste of resources to import a texture for it.

mask out 1 channel of a texture coordinate.

either red or green depending on the direction you want the gradient, than you can flip the gradient if needed by useing the -1 node, and if you need to tighten the gradient use the power node.

hope that helps.






you may want to also constant clamp the result between 0 and 1 i think there might be some above 1 and beloew 0 values in there depending on how the texture coordinate is set.



vectors in UDK, and images are interchangeable only difference is some vectors will be above 1 or below 0 with some of there values so they will need to be clamped if you want to use them in a non standard way.

Qwiggalo

Yeah that helps, thanks!

passerby

you call also change the values in the texture coord to move the gradient up so it goes from white to black to white again, just change the V tiling value to above 1.

V is the green channel and U and the red.

Qwiggalo

I was really close to figuring it out, I just didn't know that G on a mask is V and R is U.

passerby

Qwiggalo wrote: »

I was really close to figuring it out, I just didn't know that G on a mask is V and R is U.

well just think of the order

UVW to RGB or in the case of the texture coordnate just UV and Red and green

the same goes for vectors in of world coordinates

XYZ RGB

expect in that case it is more obvious since if you look in the bottom corner of any 3d viewport in udk you can see the XYZ using RGB for it's color coding.