How do I stop images being distorted in Unity3d? - image

I am making an app in Unity but when I add graphics, they are distorted and out of proportion. I am able to use them, but they don't look good. How do I fix it?

When imported, images default to Texture format which will make them power of two (to be used as textures in 3D space.) If you meant to use them as 2D textures, you will have to update the values in the texture import setting panel to GUI. You can also change or even disable compression if higher quality is needed.

Related

Animated texture quality very bad

I'm trying to create a short opener for a clip by using a plane and an animated texture. I created the animated texture sheet, frame by frame, in photoshop. It's a large texture, 12x12 frames. When I try playing it in unity, while it works, it is of a significantly lower quality.
I have seen posts about tweaking my import settings, but these are the only ones I see (no max size etc)
I did have to use an older version of unity to make it work with the rest of the project I was working on - is that the problem? I feel like even older versions should be capable of generating good quality
Disable mipmaps. Mipmaps are downsized versions of your texture used for rendering at different distances. If the distance you have your image from the camera is far enough, Unity will use one of those smaller versions, making it blurry.
Disable blend mode (set it to 'Point'). Bilinear Filtering slightly blurs textures so that they scale better or render at sub-pixel positioning better. However, this makes them less crisp.
You may want to set the texture mode from 'Default' to 'Sprite 2D' or 'GUI', I'm not sure what version of Unity you're on (2017?) as I don't recognize the layout of the inspector you have there. Sprite 2D settings tend to optimize for images that are intended to be pixel perfect, same goes for GUI textures.

How to draw on an image in openGL?

I load an image (biological image scans) and want to a) display it and b) draw markers on it. How would I program the shaders? I guess the vertex shaders are simple enough, since it is an 2D image. On idea I had was to overwrite the image data in the buffer, the pixels with the markers set to a specific values. My markers are boxes (so lines), is this the right way to go? I read that there are different primitives, lines too, so is there a way to draw my lines on my image without manipulating the data in the buffer, simply an overlay, so to speak? My framework is vispy, but pseudocode would also help.
Draw a rectangle/square with your image as a texture on it. Then, draw the markers (probably as monotone quads/rectangles).
If you want the lines to be over the image, but under the markers, simply put the rendering code in between.
No shaders are required, if older OpenGL is suitable for you (since OpenGL 3.3 most old stuff was moved to compatibility profile, while modern features are core profile; the latter requires self-written shaders, but they should be pretty simple for your case).
To sum up, the things that you need understanding of are primitives (lines, triangles) and basic texturing.

LibGDX - Sprite to Pixmap

I am using LibGDX for a small app project, and I need to somehow take a series of sprites and place them (or their pixels rather) into a Pixmap. The basic idea is to take random sprites that are generated through various means while the app is running, and, only at specific times, merge some of them onto a single background sprite.
I believe that most of this can be done easily, but the step of getting the sprite images into the Pixmap isn't quite so obvious to me. The sprites also have various transparent and semi-transparent pixels, so simply grabbing the color at each pixel while it is all on the same screen isn't really applicable either, as it obviously shouldn't take the background colors with it.
If there is a suitable alternative to this that would accomplish what I am looking for I would also love to hear it. Any help is highly appreciated.
I think you want to render your sprites to an off-screen buffer (called an "FBO" or FrameBuffer in libgdx) (blending them as they're added), and then render that offscreen buffer to the screen as a single draw call? If so, this question should help: libgdx SpriteBatch render to texture
This requires OpenGL ES 2.0, which will eliminate support for some older devices.

What can we use instead of blending in OpenGL ES?

I am doing my iPhone graphics using OpenGL. In one of my projects, I need to use an image, which I need to use as a texture in OpenGL. The .png image is 512 * 512 in size, its background is transparent, and the image has a thick blue line in its center.
When I apply my image to a polygon in OpenGL, the texture appears as if the transparent part in the image is black and the thick blue line is seen as itself. In order to remove the black part, I used blending:
glEnable(GL_BLEND);
glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
Then my black part of the texture in the polygon is removed. Now only the blue band is seen. Thus the problem is solved.
But I want to add many such images and make many objects in OpenGL. I am able to do that, but the frame rate is very low when I add more and more images to objects. But when I comment out blending, the frame rate is normal, but the images are not seen.
Since I do not have good fps, the graphics are a bit slow and I get a shaky effect.
So:
1) Is there any other method than blending to solve my problem?
2) How can I improve the frame rate of my OpenGL app? What all steps need to be taken in order to implement my graphics properly?
If you want to have transparent parts of an object, the only way is to blend to pixel data for the triangle with what is currently in the buffer (what you are currently doing). Normally, when using solid textures, the new pixel data for a triangle just overwrites what ever was in buffer (as long as it is closers, ie z-buffer). But with transparency, it has start looking at the transparency of that part of the texture, look at what is behind it, all the way back to something solid. Then has combine all of those over lapping layers of transparent stuff till you get the final image.
If all you are wanting your transparency for is something like a simple tree sprite, and removing the 'stuff' form the sides of the trunk etc. Then you may be better of providing more complex geometry that actually defines the shape of the trunk and thus not need to bother with transparency.
Sadly, I don't think there is much you can do to try to speed up your FPS, other then cut down the amount of transparency you are calculating. Maybe even adding some optimization that checks images to see if it can turn of alpha blending for this image or not. Depending on how much you are trying to push through, may save time in the long wrong.

Copy arbitrarily sized block of pixels into OpenGL ES texture... somehow?

I'm writing a drawing application, and the drawing canvas is an OpenGL texture. When you draw onto the canvas, it determines which region of the canvas texture has been changed, and copies that pixel data out (using glReadPixels) before applying the changes you made.
To undo, I want to simply revert to the previous texture state using that pixel data that was copied out. However, OpenGL ES doesn't provide a glDrawPixels command. What's the best way to do it?
I've considered two options, but I'm not sure either is that great:
Create a temporary texture using the pixels I copied out and draw that in. (However, copied region is not a power of two!)
Unbind the large canvas texture completely, manually alter the bytes of the texture, and then put it back into OpenGL. I'm not using any sort of compression, so this might not be that bad. But it seems like a hack?
Anybody have any ideas? I'd really appreciate it!
In case anyone stumbles across this while trying to do something similar, I've come up with a solution that seems to work well.
Grab an image of the current texture by binding it to the framebuffer and then writing the framebuffer to a CGImageRef.
Create a new CGContext and draw in the existing texture CGImageRef. Then draw old texture data in to the portion that the user changed, effectively "undoing" that change to the image.
Destroy old OpenGL texture and create a texture from the CGContext.
I think this is a pretty slow way of going about things, but I don't need huge performance - my real concern was limiting the amount of data being kept to represent the "old" texture.
If you need help with this (there's quite a bit of code) feel free to email me.

Resources