Thank you so much! Looking forward to using this patch instead of my workaround :)
On Fri, May 28, 2021 at 9:50 AM Larry Gritz <l...@larrygritz.com> wrote: > I think this is the fix: https://github.com/OpenImageIO/oiio/pull/2981 > > Thanks for alerting me to this bug, Daniel. > > > On May 27, 2021, at 11:22 PM, Larry Gritz <l...@larrygritz.com> wrote: > > Aha, there does seem to be a bug. The docs say that render_text ought to > be doing an "over", but you are right, it's not behaving that way at all! > > Your understanding of what *should* happen is also how I thought it > worked. It's just a mistake somewhere, I will try to find a fix. > > -- lg > > > On May 27, 2021, at 12:35 AM, Daniel Flehner Heen <flehnerhee...@gmail.com> > wrote: > > Hi Larry! > > Apologize for the lack of response. > > Inspecting the values indeed show variations in the alpha channel, so it > works and this turns out to be a case of misconception from my side. > I assumed that render_text would do an "over" and that by setting alpha of > text color to values below 1 would yield "see through" text rather than > directly manipulating the pixels in the buffer. > > Thank you for your help! > > > > On Tue, May 25, 2021 at 9:31 PM Larry Gritz <l...@larrygritz.com> wrote: > >> Sorry, of course I meant (1+0.6*something). The 0.4 is opacity, not >> transparency. >> >> A over B = A + (1-A.alpha)*B >> >> >> On May 25, 2021, at 12:30 PM, Larry Gritz <l...@larrygritz.com> wrote: >> >> Well, you have set the text color to (1,1,1,0.4), so if you put that >> "over" an image, then write to (or display on) a LDR device or file, the >> resulting "clamp" to the full intensity of the output will not be >> distinguishable from if it were opaque. But if you are inspecting values in >> an HDR format like OpenEXR, then the values of text (1,1,1,0.4) over >> "something" will be (1+0.4*something, ...), whereas opaque (1,1,1,1) over >> "something" will be exactly (1.0, ...) no matter what the something is. >> Note that for both of those, if clamped to a max of 1.0, they will look the >> same. >> >> >> On May 25, 2021, at 12:18 PM, Daniel Flehner Heen < >> flehnerhee...@gmail.com> wrote: >> >> Hmmm. I've only checked visually, but when rendering on an image I can't >> see through the text. If you get transparency I must be doing >> something wrong. >> I'm not in front of a computer at the moment, but I'll try and break down >> my process and see if I can figure it out. >> I'll let you know what I find. >> >> Thanks, >> >> >> >> >> >> On Tue, May 25, 2021, 21:01 Larry Gritz <l...@larrygritz.com> wrote: >> >>> Works for me. How are you determining that there is "no difference in >>> transparency"? Are you inspecting the alpha values in the output file? Are >>> you compositing on top of something? >>> >>> >>> On May 25, 2021, at 11:58 AM, Daniel Flehner Heen < >>> flehnerhee...@gmail.com> wrote: >>> >>> Sorry, should have been more specific. >>> There seems to be no difference in the text's transparency for values >>> between 0.1 and 1.0 for the alpha channel. >>> >>> On Tue, May 25, 2021, 20:48 Larry Gritz <l...@larrygritz.com> wrote: >>> >>>> What happens, specifically? >>>> >>>> >>>> On May 25, 2021, at 6:31 AM, Daniel Flehner Heen < >>>> flehnerhee...@gmail.com> wrote: >>>> >>>> Hi! >>>> >>>> I'm attempting to render text with 40% opacity in python without >>>> success. OIIO 2.2.10.1 >>>> >>>> ``` python >>>> import OpenImageIO as oiio >>>> buf = oiio.ImageBuf(oiio.ImageSpec(640, 480, 4 oiio.FLOAT)) >>>> oiio.ImageBufAlgo.render_text(buf, 100, 200, "Hello, World!", 60, >>>> "FreeSans", (1, 1, 1, 0.4)) >>>> buf.write('transparent_text_test.exr') >>>> ``` >>>> >>>> Am I doing something wrong? >>>> Any pointers would be greatly appreciated. >>>> >>>> Thanks, >>>> >>>> -- >>>> -Daniel >>>> _______________________________________________ >>>> Oiio-dev mailing list >>>> Oiio-dev@lists.openimageio.org >>>> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org >>>> >>>> >>>> -- >>>> Larry Gritz >>>> l...@larrygritz.com >>>> >>>> >>>> >>>> >>>> _______________________________________________ >>>> Oiio-dev mailing list >>>> Oiio-dev@lists.openimageio.org >>>> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org >>>> >>> _______________________________________________ >>> Oiio-dev mailing list >>> Oiio-dev@lists.openimageio.org >>> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org >>> >>> >>> -- >>> Larry Gritz >>> l...@larrygritz.com >>> >>> >>> >>> >>> _______________________________________________ >>> Oiio-dev mailing list >>> Oiio-dev@lists.openimageio.org >>> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org >>> >> _______________________________________________ >> Oiio-dev mailing list >> Oiio-dev@lists.openimageio.org >> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org >> >> >> -- >> Larry Gritz >> l...@larrygritz.com >> >> >> >> >> >> -- >> Larry Gritz >> l...@larrygritz.com >> >> >> >> >> _______________________________________________ >> Oiio-dev mailing list >> Oiio-dev@lists.openimageio.org >> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org >> > > > -- > -Daniel > _______________________________________________ > Oiio-dev mailing list > Oiio-dev@lists.openimageio.org > http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org > > > -- > Larry Gritz > l...@larrygritz.com > > > > > _______________________________________________ > Oiio-dev mailing list > Oiio-dev@lists.openimageio.org > http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org > > > -- > Larry Gritz > l...@larrygritz.com > > > > > _______________________________________________ > Oiio-dev mailing list > Oiio-dev@lists.openimageio.org > http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org > -- -Daniel
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