Fixing Low Resolution With Vedo And PySide6 Embeddings

When embedding 3D visualizations into PySide6 applications, developers sometimes encounter issues with low resolution, particularly noticeable when dealing with text elements. This article delves into the problem of low resolution when embedding vedo plotters into PySide6 applications, offering a detailed explanation and potential solutions. We'll explore the common causes, provide a practical code example demonstrating the issue, and discuss strategies to achieve sharper, more visually appealing renderings within your PySide6 interfaces. This is particularly crucial when your visualizations include detailed text or intricate geometries that demand clarity. By understanding the underlying factors contributing to this problem, you can ensure your PySide6 applications deliver a professional and user-friendly experience.

Understanding the Resolution Problem

The challenge of low resolution in embedded visualizations often stems from the way the rendering context is handled between the 3D plotting library (like vedo) and the Qt framework (PySide6). When a 3D scene is rendered within a PySide6 widget, the default settings might not adequately scale the rendering to match the widget's dimensions or the screen's pixel density. This can lead to blurry text, jagged lines, and an overall reduction in visual fidelity. This section will clarify the importance of high-resolution rendering in PySide6 applications and how low resolution can negatively impact user experience. We will also delve into the technical reasons behind the resolution discrepancy, such as viewport size, pixel density, and rendering parameters. Understanding these factors is the first step in effectively addressing the issue and achieving optimal visual quality in your embedded visualizations. By identifying the root causes, developers can implement targeted solutions to ensure their applications display 3D content with the clarity and detail required for a professional and engaging user experience.

Code Example Demonstrating the Issue

To illustrate the problem, let's examine a code example using vedo and PySide6. The code below creates a simple PySide6 window with an embedded vedo plotter. It renders a cone with accompanying text and axes. Running this code often reveals the low resolution issue, especially noticeable in the rendered text. This code will serve as a practical demonstration of the challenges developers face when integrating 3D visualizations into PySide6 applications. By examining the code and its output, you can directly observe the impact of low resolution on the visual clarity of the embedded scene. This hands-on experience is invaluable in understanding the problem and motivating the need for effective solutions. The subsequent sections of this article will build upon this example, providing strategies to enhance the rendering quality and achieve the desired level of visual fidelity.

import sys
from PySide6.QtWidgets import QMainWindow, QFrame, QVBoxLayout, QApplication
from vtkmodules.qt.QVTKRenderWindowInteractor import QVTKRenderWindowInteractor
from vedo import Cone, Axes, Plotter

class MainWindow(QMainWindow):

    def __init__(self, parent=None, qt_widget=True):

        QMainWindow.__init__(self, parent)
        self.frame = QFrame()
        self.layout_ = QVBoxLayout()

        if qt_widget:
            self.vtkWidget = QVTKRenderWindowInteractor(self.frame)
            self.layout_.addWidget(self.vtkWidget)

        else:
            self.vtkWidget = None

        self.plt = Plotter(qt_widget=self.vtkWidget)

        self.frame.setLayout(self.layout_)
        self.setCentralWidget(self.frame)

        self.create_show_objs()
        self.show()

    def create_show_objs(self):
        cone = Cone().rotate_x(30).rotate_z(20).c('steelblue')

        txt  = "Japanese\nこれは青い円錐形です\n"
        txt += "Chinese\n這是一個藍錐\n"
        txt += "Russian\nЭто синий конус\n"
        txt += "English\nThis is a blue cone"

        capt = cone.caption(txt, size=(0.4,0.3), font="LogoType", c='lb')

        axes = Axes(
            cone,
            xtitle='マイクロメートル単位のx軸',
            ytitle='y軸にも長い説明があります',
            ztitle='Z軸始終來自中國',
            title_font='LogoType',
            text_scale=1.5,
            c='white',
        )

        self.plt.show(cone, capt, axes, viewup='z', bg='k', bg2='bb')

if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = MainWindow(qt_widget=False)
    app.exec_()

Key elements of the code:

• It imports necessary modules from PySide6, vtk, and vedo.
• It defines a MainWindow class inheriting from QMainWindow.
• It creates a QVTKRenderWindowInteractor widget to embed the vedo plotter.
• It creates a vedo Plotter instance, associating it with the Qt widget.
• It defines a create_show_objs method that generates a cone, text caption, and axes.
• It uses self.plt.show to display the objects within the vedo plotter.
• The if __name__ == "__main__": block creates a PySide6 application and runs the MainWindow.

Analyzing the Output

When you run this code, observe the embedded visualization. You'll likely notice that the text in the caption and axes titles appears blurry or pixelated. The cone itself might also lack sharpness. This low resolution is the problem we aim to address. This visual deficiency underscores the importance of finding effective solutions for high-resolution rendering in PySide6 applications. The subsequent sections will explore various techniques to improve the visual quality of your embedded visualizations, ensuring that text and other details are rendered with clarity and precision. By addressing this issue, developers can create more professional and user-friendly applications that leverage the power of 3D visualization.

Common Causes of Low Resolution

Several factors can contribute to low resolution in embedded visualizations. Understanding these causes is crucial for implementing effective solutions. One common culprit is the viewport size of the VTK render window, which might not be properly synchronized with the PySide6 widget's dimensions. If the render window is smaller than the widget, the visualization will be scaled up, leading to pixelation. Another factor is the pixel density of the display. High-DPI displays require higher rendering resolutions to avoid blurriness. Furthermore, the rendering parameters used by vedo (or any other 3D plotting library) can also affect the output resolution. Default settings might prioritize performance over quality, resulting in lower resolution renderings. This section will provide a comprehensive overview of these common causes, equipping developers with the knowledge to diagnose the specific issues affecting their applications. By identifying the root causes, you can select the most appropriate solutions and ensure your PySide6 applications deliver visually stunning and clear 3D visualizations.

• Viewport Size: The dimensions of the rendering area within the VTK render window. If this is smaller than the PySide6 widget, the image will be scaled up, causing pixelation.
• Pixel Density (DPI): High-DPI displays require higher rendering resolutions to maintain sharpness. If the application doesn't account for DPI scaling, the visualization will appear blurry.
• Rendering Parameters: Vedo and other 3D libraries have rendering settings that affect quality. Default settings may prioritize performance over resolution.
• Qt Widget Configuration: The way the PySide6 widget is configured, including its size policy and layout, can impact the available rendering space.

Solutions for Enhancing Resolution

Fortunately, several techniques can be employed to enhance the resolution of embedded visualizations in PySide6. This section will delve into practical solutions that address the common causes discussed earlier. One effective approach is to explicitly set the render window size to match the PySide6 widget's dimensions. This ensures that the visualization is rendered at the correct scale, preventing pixelation due to upscaling. Another crucial step is to handle DPI scaling properly. PySide6 provides mechanisms to detect the screen's pixel density and adjust the rendering resolution accordingly. Additionally, you can fine-tune the rendering parameters within vedo to prioritize quality over performance. This might involve increasing the number of samples used for anti-aliasing or adjusting the texture resolution. This section will provide detailed guidance on implementing these solutions, empowering developers to achieve high-resolution renderings in their PySide6 applications. By mastering these techniques, you can create visually appealing and professional-looking applications that effectively leverage the power of 3D visualization.

1. Adjusting Viewport Size

Ensuring the viewport size matches the PySide6 widget dimensions is crucial for preventing pixelation. This involves programmatically setting the render window size to match the widget's size. Here’s how you can achieve this:

• Retrieve Widget Size: Obtain the width and height of the PySide6 widget using widget.width() and widget.height().
• Set Render Window Size: Use the vedo's Plotter method, or the underlying VTK render window's method, to set the viewport size to the retrieved dimensions.

This approach guarantees that the visualization is rendered at the correct scale, eliminating the need for upscaling and preserving image clarity. By implementing this solution, you can address one of the most common causes of low resolution and ensure your embedded visualizations appear sharp and detailed.

2. Handling DPI Scaling

High-DPI displays require special handling to prevent blurriness. PySide6 provides tools to detect the screen's pixel density and scale the application accordingly. Here's how to handle DPI scaling:

• Enable High-DPI Scaling: In your PySide6 application, enable high-DPI scaling using QApplication.setAttribute(Qt.AA_EnableHighDpiScaling, True) and QApplication.setAttribute(Qt.AA_UseHighDpiPixmaps, True). These attributes instruct PySide6 to automatically scale the application's UI elements based on the screen's DPI.
• Scale Rendering Resolution: Obtain the screen's device pixel ratio using window.devicePixelRatio() (where window is your QMainWindow instance). Multiply the desired rendering resolution by this ratio to achieve the correct scaling for high-DPI displays.

By correctly handling DPI scaling, you can ensure that your visualizations appear crisp and clear on high-resolution displays. This is essential for delivering a professional and user-friendly experience, particularly for applications that are likely to be used on a variety of devices with different screen densities.

3. Optimizing Rendering Parameters

Vedo offers several rendering parameters that can be adjusted to enhance visual quality. Experimenting with these settings can significantly improve the resolution and clarity of your embedded visualizations. Some key parameters to consider include:

• Anti-Aliasing: Enable anti-aliasing to smooth out jagged edges. You can increase the number of samples used for anti-aliasing to achieve a higher level of smoothness.
• Texture Resolution: If your visualization includes textures, ensure that the texture resolution is sufficient for the display size. Low-resolution textures can appear blurry when scaled up.
• Line Width: Adjust the line width to make lines appear sharper and more defined. A larger line width can improve visibility, especially for intricate geometries.
• Shadow Quality: If shadows are enabled, experiment with different shadow quality settings to find a balance between visual fidelity and performance. Higher shadow quality settings can improve the realism of the visualization but may also impact rendering speed.

By fine-tuning these rendering parameters, you can optimize the visual quality of your embedded visualizations while maintaining acceptable performance. This iterative process of experimentation and adjustment allows you to tailor the rendering settings to the specific requirements of your application and achieve the desired level of visual fidelity.

Conclusion

Achieving high-resolution embeddings in PySide6 requires a comprehensive understanding of the factors that contribute to low resolution and the techniques available to mitigate them. By addressing issues like viewport size, DPI scaling, and rendering parameters, developers can create PySide6 applications with stunning 3D visualizations. This article has provided a detailed guide to diagnosing and resolving resolution problems in embedded vedo plotters, empowering you to deliver a superior user experience. Remember, the key to success lies in a systematic approach: identify the root cause, implement the appropriate solution, and iteratively refine your settings until you achieve the desired visual quality. By mastering these techniques, you can unlock the full potential of 3D visualization in your PySide6 applications, creating engaging and informative user interfaces.