Avoid rendering in both the opaque and transparent pass? #810
Description
If render_mask=0 then often objects will render in both the opaque and transparent pass
See for example the text shader
pygfx/pygfx/renderers/wgpu/shaders/textshader.py
Lines 87 to 90 in cba5dd1
In some benchmarks of mine: I've found that this can actually cause you to pay twice for the rendering the object
pygfx/pygfx/renderers/wgpu/engine/renderer.py
Lines 656 to 659 in cba5dd1
So its quite difficult to actually show the effect, but what i tried to do is to generate about 1000 pieces of text on the screen
on the left window, i specified render_mask=2 and on the right render_mask=0.
with render_mask=2 (transparent) I can reach about 27 fps, with render_mask=0 i can't get past about 22.
the code
import os
import random
from wgpu.gui.auto import WgpuCanvas, run
import pygfx as gfx
import argparse
parser = argparse.ArgumentParser(description="Render Mark with Too Much Text")
parser.add_argument(
"--render-mask", type=int, default=1, help="Render mask parameter"
)
args = parser.parse_args()
render_mask = args.render_mask
scene = gfx.Scene()
scene.add(gfx.Background.from_color("#fff", "#000"))
material = gfx.TextMaterial(color="#B4F8C8", outline_color="#000", outline_thickness=0.15)
assert material.aa
for i in range(1000):
text = gfx.Text(
gfx.TextGeometry(
text=f"{i}",
font_size=40,
screen_space=True,
),
material=material,
render_mask=render_mask,
)
text.local.position = (
# Random number between -400 and 400
random.randint(-400, 300),
random.randint(-300, 200),
0)
scene.add(text)
canvas = WgpuCanvas(title=f"Render Mask {render_mask}")
renderer = gfx.WgpuRenderer(canvas)
camera = gfx.OrthographicCamera(800, 600)
controller = gfx.PanZoomController(camera, register_events=renderer)
if __name__ == "__main__":
canvas.request_draw(lambda: renderer.render(scene, camera))
run()I used mangohud to display the fps
I guess mangohud also shows that with render_mask=0 the utilization is higher than with render_mask=2.