Ok, hey guys. This is the first time I've had to ask a question myself, since I can't seem to find what I'm looking for anywhere.
I'm using Cocos2D and CCDrawingPrimitives to draw points with a fade.
It was working perfectly. Now, instead of going transparent, the points just get more and more white. I didn't change anything in the code either so it's annoying. Anyway I'm seeing the same issue within other areas of my app as well. When I want transparency I get a blend of the original colour over pure white.
I've tried alot of different blend combinations etc.
I have kind of fixed the problem by fading the brightness of the colour as I lower the alpha. but it was much better before since on anything other than white the reducing brightness is a bit noticeable...
Any help is appreciated. Thank you.
Related
I am getting difficulties for making this color view.
As you can see, this is not a single color.
I am struggling to get this colored view but seems like my skill is not enough for getting this color.
I am always eager to learn but for this time, I don't know how to I get this color.
The bars you are pointing to are nearly saturated magenta, roughly #ff64ff. However, they also have a bit of linear gradient on them to give them the tube shape, and a magenta "shadow" to give them glow effect. How to get them would be very dependent on the system you are using to draw them.
My App's background is an opaque UIImageView. Under some circumstances I would like to darken this down in an animated way from full brightness to about 50%. Currently I lower the alpha property of the view and this works well. Because nothing is behind the view, the background image just becomes dark.
However, I've been profiling using the Core Animation Instrument and when I do this, I see that the whole background shows as being blended. I'd like to avoid this if possible.
It seems to me that this would be achievable during compositing. If a view is opaque, it is possible to mix is with black without anything behind showing through. It's not necessary to blend it, just adjust the pixel values.
I wondered if this was something that UIKit's GPU compositing supports. While blending isn't great, it's probably a lot better than updating the image on the CPU, so I think a CPU approach is probably not a good substitute.
Another question asks about this, and a few ideas are suggested including setting the Alpha. No one has brought up a mechanism for avoiding blending though.
An important question here is whether you want the change to using a darkened background to be animated.
Not animated
Prepare two different background images and simply swap between them. The UIImage+imageEffects library could help with generating the darkened image, or give you some leads.
Animated.
Take a look at GPUImage - "An open source iOS framework for GPU-based image and video processing". Based on this you could render the background in to the scene in a darkened way.
I have been working with OpenGL in iOS, and setting the colors with glColor4f(r,g,b,a) and then drawing my own color on a white UIImageView. I basically have a brush, which is then moved around my user's touch, and then it paints the color onto the canvas. But this color needs to be water paint (like smudged color)
Does anyone understand/knows how to get a water color like this app does, and how the background UIImageView has a texture on it?
https://itunes.apple.com/us/app/hello-watercolor/id539414526?mt=8
or checkout water paint in this. http://www.fiftythree.com/paper
I created a bounty on this as I am really having a hard time to grasp how to derive such smooth flowing colors out of the normal colors. Even if you guys point me in the right direction, or to some sample code on how I can get the effect of water-paint, it would be really helpful ^_^
And as a bonus, it would be also be helpful if you can point out to me how to get canvas on which it is painted on looks realistic, and blended with the paint? Does Blending/GLSL have to do with any of this?
Is there any sample project on this?
If you are still struggling with the basics of getting realistic looking water colors working, you may want to experiment/prototype in photoshop first.
http://www.zoepiel.com/tutorials/watercolor/ shows some very effective tricks for creating watercolor images with simple tools.
The most interesting one is to multiply a group of watercolor layers with a greyscale watercolor paper image. The texture of the paper makes some parts remain white, and other parts saturate with color, just like real watercolor.
Each layer remains 'wet' in the sense that the colors within it blend, but the layers are 'dry' with respect to each other.
She also explains some of her brush and blur settings and shows what they do.
Once you can produce the desired effect in photoshop, you'll have clear specifications of what you want to do and you'll be quite a bit closer to programming it out.
Looking at the examples you posted, it looks like they are using a simple Gaussian Blur with a radius of double your brush size. This may be an incomplete solution, but it's at least the first level.
I have been working with OpenGL in iOS, and setting the colors with glColor4f(r,g,b,a) and then drawing my own color on a white UIImageView. I basically have a brush, which is then moved around my user's touch, and then it paints the color onto the canvas. But this color needs to be water paint (like smudged color)
Does anyone understand/knows how to get a water color like this app does, and how the background UIImageView has a texture on it?
https://itunes.apple.com/us/app/hello-watercolor/id539414526?mt=8
or checkout water paint in this. http://www.fiftythree.com/paper
I created a bounty on this as I am really having a hard time to grasp how to derive such smooth flowing colors out of the normal colors. Even if you guys point me in the right direction, or to some sample code on how I can get the effect of water-paint, it would be really helpful ^_^
And as a bonus, it would be also be helpful if you can point out to me how to get canvas on which it is painted on looks realistic, and blended with the paint? Does Blending/GLSL have to do with any of this?
Is there any sample project on this?
If you are still struggling with the basics of getting realistic looking water colors working, you may want to experiment/prototype in photoshop first.
http://www.zoepiel.com/tutorials/watercolor/ shows some very effective tricks for creating watercolor images with simple tools.
The most interesting one is to multiply a group of watercolor layers with a greyscale watercolor paper image. The texture of the paper makes some parts remain white, and other parts saturate with color, just like real watercolor.
Each layer remains 'wet' in the sense that the colors within it blend, but the layers are 'dry' with respect to each other.
She also explains some of her brush and blur settings and shows what they do.
Once you can produce the desired effect in photoshop, you'll have clear specifications of what you want to do and you'll be quite a bit closer to programming it out.
Looking at the examples you posted, it looks like they are using a simple Gaussian Blur with a radius of double your brush size. This may be an incomplete solution, but it's at least the first level.
I am trying to create a spotlight effect in my story book such that as the character moves around from one location to the other then the light focus moves towards that same character.Is it possible to do that in Corona SDK? How can I do that coz sprites aren't
helping me.Any idea regarding this.
I found some reference telling me that I can't do that
http://web-c2.anscamobile.com/forum/2012/10/27/dynamic-shadows-2d
http://developer.coronalabs.com/forum/2012/09/13/lightingshadows
Those two threads seem pretty definitive. You could create a spotlight pretty easy, but you can't cast shadows and the light moves different directions very easily.
If you want to do a spotlight without shadows, just create an image that's all black with a transparent hole in them middle that has some feathering around the hole. Make the black partially transparent so you can see the scene but have it a bit darker. You can them move the image around to be your spot light. You can also do it with a maskk (see the Flashlight example in the sample code)