Is it possible to add a red tint to a given camera in SceneKit? I would like to accomplish this without the (what I consider to be) hacky solution of just trying to shove a red object with < 1 opacity in front of the camera. That could be a solution but I haven't had great success in SceneKit showing an object right in front of the camera.
Also, ideally, I could fade the red tint in and out using SCNAction or some other way.
Finally, a perfect solution would work in ARKit, and give a red tint to the whole world around you. So it would have to be something more than a red scenekit light.
SCNCamera's colorGrading property can do that (that would be the most efficient option).
Using a SCNTechnique to apply a custom post process would work too but it requires an additional pass.
Both options would be faster than a blended node in front of the camera, or a red-ish spritekit overlay or a UIView on top of the SCNView.
Instead of adding a red-tinted SCNNode into the scene, you could just add a tinted UIView in front of the ARSCNView in the storyboard. With an outlet to that view fading it in and out would be easy.
Related
i got 2 models on my scene (using SceneKit) - ring and diamond. Ring is with gold pbr material (SCNLightingModelPhysicallyBased) - second is diamond with "custom" material using Metal shader (SCNProgram). Right after developing diamond shader my golden ring stopped working and is pure black. Why is that ? When i simply set my ring to yellow and drop pbr lighting model it works, just not pbr - with pbr its solid black. I cant use SCNProgram with PBR ?
Are you setting the scene's lightingEnvironment? You will need a light source in the scene for the object to be lit. You can either use point lights or leverage image-based lighting (IBL) which is what the lightingEnvironment is for.
You can also try the autoenablesDefaultLighting property. With it SceneKit will try to adjust and add light sources in the scene depending on its contents, but its behaviour is subject to changes.
I'm trying to build a 3D earth with Wpf Viewport3D. I have created the earth and it works pretty good. Then I want to add a halo effect around the earth like this attached image:
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Some recommend to use diffuse material for the globe model. Then build a slight larger globe model with emissive material and little opacity. But the effect is not very good. It affects the color of diffusion material like this:
How can I implement the effect like the first screenshot?
I've done exactly this by creating a ring, inner radius the same radius as the planet and an outer radius to relect the atmospheric depth. Oriented to 'face me'. Using texture coordinates into a LinearGradientBrush to have the atmosphere fade from sky blue to transparent black.
Alternatively, there are some fairly good PNGs around of semi-transparent cloud layers you could use on the slightly larger sphere.
I've been searching for awhile, but haven't been able to find anything. I'd like to be able to add kind of a glimmer or sparkly animation on an image element in wpf.
Essentially the effect here I'm after here is the same that you get with trading cards that are "foil's".
I'd like to have an image, and then be able to add this animation to it at will. I'm thinking maybe some kind of user control, or template possibly. Hopefully generic enough that I can just toss an image at it and it will just overlay the image and run.
Any ideas?
A simple construction that easily can be turned into a control is by nesting the image in a Grid and adding a second Grid (on top) as a sibling.
De second grid can be given a linear gradient brush that is primarily transparent but does contain a white glimmer.
This brush can be animated; you could move it and change the opacity of the grid/brush.
This way you do not change the image.
Before drawing a shape on a canvas I have a preview that displays how the shape will look. I can adjust the opacity and then draw the shape. I may then wish to draw a second shape with a different opacity. My problem is that altering the opacity of the preview also alters the opacity of the shape that I have already drawn.
This has led me to believe that I need to create a copy of the brush used for the preview each time before drawing the shape.
There are various different brushes and for example, the gradient brushes require making a copy of the not just the gradient stop collection, but a new gradient stop for each gradient stop in the to-be-copied collection.
Am I down the right track here or should I be doing something else? Should I be copying or cloning? Would an extension method be the best way to go? Thoughts please.
What you need is cloning, it would be easy in wpf with XamlWriter/Reader, unfortunately you cannot do it in Silverlight. An extension method on Brush that makes a deep copy would work fine in your case though. You will have to handle the different brush type separately but it should not be an issue as there aren't that many.
The System.Drawing.Graphics class has a property CompositionMode with two options: SourceOver (which, based on the alpha component, blends whatever is drawn with the background already existing) or SourceCopy which simply overwrites the background with whatever is being drawn.
Does something similar exist in WPF?
In WPF when i draw a PolyLine for example on top of another the new PolyLine always alphablends with the background. I think that is independent of the container being used. I am using a Canvas but could not find a blend mode property anywhere. What I want to do is what the SourceCopy compositionmode mentioned above does. I.e. the new PolyLine should simply overwrite whatever is already on the Canvas.
Is there a simple way to do that, short of using pixel shaders (which - as far as I understand - wouldn't work anyways because I don't have access to the Canvas backbuffer).
I am not stuck with a Canvas and would be happy to use any container that supports overwrite mode.
I currently have a solution based on a WriteableBitmap for which I obtain a System.Drawing.Graphics context and then manipulate the CompositionMode. It works but since my window is fullscreen that solution has serious performance impacts.
Clarification and example:
The WPF window is fully transparent and so is the Canvas (back ground color(0,0,0,0)). Now I draw a PolyLine with a Color.FromArgb(128,128,0,0). I now have a semi-transparent red polyline. Next I draw the same PolyLine with Color.FromArgb(0,0,0,0). The result is the same as before because of the alpha blending taking place. What I want, however, is that the red polyline is erased with the second polyline (which is exactly what the SourceCopy mode in the Graphics class does.
I think all you need to do is make sure that the brushes used to fill/stroke the PolyLine have fully opaque alpha values (i.e. 255). Then the background shouldn't be blended into it.
You could apply a Clipping Mask, this way you can provide the path to clip over the elements that are below it, but it might be tough to maintain after a lot elements are required to be clipped...