My guns have a certain range. When hovering over one I want to demonstrate what that means. So I've added a 3d-object (a flattened cylinder) which I want to show/hide onMouse-enter/leave.
But first I need it to be transparent - I've searched and found how - It's materials rendering mode must be transparent, and the color must have an alpha value (here 128).
But it looks VERY SOLID BLACK to me...?
Related
I am trying to minimize SetPass calls in Unity canvas.
Consider the following example:
The rendering in canvas happens layer by layer. The rendering sequence can be like the following:
Red squares (+1 set pass call)
Text "1" and yellow squares (+2 set pass call)
Text "2" and pink square (+2 set pass call)
Text "3" (+1 set pass call)
Or, it might be a little better:
Red squares (+1 set pass call)
Yellow squares and then text "1" (+1 set pass call)
Pink square and then texts "2" and "3" (+2 set pass calls)
Because of this, drawing is switching from default image material to text material and back. The result of this drawing will produce at least 4 draw calls, instead of 2. Even though only 2 materials are in use. This example also assumes that Red, Yellow, and Pink squares weren't batched.
Question: is there a way to ensure that text will be always drawn on top?
Notes:
TextMeshPro UI material (mobile-overlay) doesn't help here.
Unity 2019.3.12.f1
All texts are actually placed as last layers (e.g. there is nothing drawing on top of them).
Batching helps sometimes. However, complex UI might use several materials. Since my intention is to always draw text over everything, isn't there a general solution for this?
Z-order makes drawing order even worse and switching between materials happens more frequently.
I have some textures containing some transparency parts (a donut, for example, which would show a transparent center). What I want to do is fill the middle of the donut (or anything else) with a plain white, in code (I don't want to have a double of all my assets that need this tweak in one part of my game).
Is there a way to do this? Or do I really have to have 2 of each of my assets?
First it is possible to change a transparent texture to not-transparent, if it wasn't then graphic editors would be in trouble.
Solution 1 - Easy but takes repetitive editing by hand
The question you should be asking yourself is can you afford the transition at run time or would have two sets of textures be more efficient; from experience I find that the later tends to be more efficient.
Solution 2 - Extremely hard
You will need a shader that supports transparency and that it marks the sections that have to be shaded white. That is, it keeps track of which area will be later filled with white. It is implied that since your "donut" is already transparent on some parts then it already uses that texture that has an alpha, but you will have to write your own shader mask and be able to distinguish which is okay to fill white and which is not (fun problem here). What you need to do is find the condition in which that alpha no longer needs to be alpha and has to be white. Once the condition is met you can change the alpha of via the Color's alpha property. The only way I see you able to do this is if there is a pattern to the objects, so that you can apply some mathematical model to them and use that to find which area gets filled. If the objects are very different then the make two sets of textures starts to look more appealing.
Solution 3 - Medium with high re-use value
You could edit the textures to have two different colors, say pink and green. Green is the area that gets turned white and pink is always transparent. When green should not be white then it is transparent. You would have to edit your textures by hand as well.
I have a to make an application that recognizes fruits. So far i have made that you can crop the image and get the color of the fruit you want. Now i am trying to get roundness of the fruit but i need the fruit to be black and the background to be white so i can find area and roundness value. This is my code so far for that part :
crop_temp = rgb2gray(crop);
threshold = graythresh(crop_temp);
bw = im2bw(crop_temp,threshold);
imshow(bw)
Crop i get passed when i crop the image. The problem gets when the fruit has a camera flash and that part stays white.
An example image is this lemon picture:
The problem is the white area in the lemon stays white after the code but i want it so that the whole lemon is black. But not just the lemon, but for other fruits to.
The problem is the white area in the lemon stays white after the code but i want it so that the whole lemon is black. But not just the lemon, but for other fruits to.
Yeah and how can you make so that the fruit is white and the background is black.
I am new to image processing so don't jump on me. I just can't find specific stuff for this.
Try this one:
fbw = ones(size(bw))-imfill(ones(size(bw))-bw);
imshow(fbw)
A brute force approach would be to check every white pixel in your image, and see if it is boxed in by black pixels in both the X and Y directions, turning it black if this is the case. This would take care of blobs inside your fruit, and shouldn't give you too many false-positives unless your fruit are strangely shaped, or you have a lot of noise around the edges of your image.
You can start by practicing with this Matlab demo, segmenting (and counting) rice in an image. In particular the part where the background is estimated.
Also helpful will be reading on Otsu's method and these two questions on background/foreground estimation on SO and DSP which take local statistics into account.
I'm working with this excellent example of converting an image to grayscale: Convert Image to B&W problem CGContext - iPhone Dev
However, for my purposes, I would like to have only pure black and pure white left in the image.
It appears that to do so, I need to pass a black and white color space to the recolor method using a call:
CGColorSpaceRef colorSpace = CGColorSpaceCreateWithName(/*black and white name*/);
However, I was unable to find the proper iOS color space names. What I found was from Mac, and the "color space names" referenced from the iOS docs does not point anywhere.
How can I properly create a black and white CGColorSpaceRef?
Thank you!
I am not familiar with a black and white only color space but what you can do is calculate the total average RGB value from all the pixels (lets call it totalAvg) and use it as a threshold. Meaning for each pixel if its rgb average is greater than the calculated totalAvg than set it to pure white, otherwise set it to pure black.
I agree it is a bit of more work but thats whay I can think of unless you find the colorspace you are looking for.
You might try creating a gray color space, then creating an indexed color space with two colors (black and white, obviously) and using that.
I want to draw with a texture brush, in a color of my choice, on a white background using OpenGLES.
I have a bitmap image which I use CG to load and turn into a texture. This bitmap is mostly black, but has a white circle in the center that I want to use as the "brush". In other words, I want the black part to vanish in the final compositing, but the white part to take on the color that I set using glColor.
The best I can get is with the blend parameters (GL_SRC_ALPHA, GL_ONE) after setting some opaque bright color is a faded color line on a grey (not pure white background). But when I set the background to pure white, the line isn't visible.
At least in the current situation, the black edges of the original texture don't appear. Most other blend combinations I'm trying cause either nothing to show up even on grey, or to see the entire brush including the black edges, which is no good.
Is anyone willing to explain to me how I should set up my texture and/or GL states to make the bright color show through on pure white, without showing the black texture edges at all? This might be a newbie question, but I've tried working through the blend math, and I still just don't understand how the colors are all being factored together.
Here's the image I'm using as the brush:
alt text http://www.coldcoffeeandjuice.com/OpaqueBrush.png
Here's some resulting output, when the background is grey, and the glColor4f is set to (1, 0, 0, 1), eg pure red, and the brush is used on a bunch of consecutive GL_POINTs. Note that what's good about this is that only the white part of the brush image shows the color red-- that's right. The bad parts is that the red which I want to be pure and bright is pale due to being blended with the background (?) and/or the white of the brush (?) so that it washes out entirely if the background is pure white. This uses the blend params as given above (src_alpha, one).
(source: coldcoffeeandjuice.com)
Here's what I want to see, given the pure red color (thanks Paintbrush):
(source: coldcoffeeandjuice.com)
Can anyone help me understand what I'm doing wrong?
Thanks!
Ok, so you're trying to "paint" a given colour (in this case "red") on to a background, using a mask for the brush shape.
You need to do the following before you start rendering the "paint":
First make sure your brush has an alpha channel that corresponds with its shape - that is the alpha channel should look similar to the brush image you posed.
Render with these states set (note space to get around wiki markup):
// Make the current material colour track the current color
glEnable( GL_COLOR_MATERIAL );
// Multiply the texture colour by the material colour.
glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
// Alpha blend each "dab" of paint onto background
glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
See also:
http://www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/colormaterial.html
http://www.khronos.org/opengles/documentation/opengles1_0/html/glTexEnv.html