Line invisible in pavlovia(seeing like a brief flash )

[ilkekav]

I am currently having an issue with transferring my experiment to Pavlovia. It’s a line reproduction task, that works locally but lines seem invisible in Pavlovia.

I tried adding a text component and show the line lengths as a text-
now I can see the text in the experiment but still can’t see lines even if I changed their width from 2 to 5.

I also tried changing spatial units to make it visible- in pixels I don’t see anything but in most of the units (norm,height etc)I only see just 1 line in brief duration like 500 ms.

I get the line lengths from a spreadsheet as you see but I also tried removing that and entering random numbers like 32 for the first trial and 97 for the response trial, - cursor starts at the last response trial’s length when I did it like this(I want cursor to move simultaneously with the line.)

and when I just changed the target_line(response trial) cursor didn’t move simultaneously with the line.

I just tried a rectangle- as I made the width bigger ( first I started with 2,5 and 100) I am able to see it on screen only for like 500 ms maybe less than that and its just 1 rectangle**
again it works locally but I don’t see anything online just grey screen

I also just tried with a triangle- I don’t get an error:

How can I fix this?

[Becca]

Hi There,

For online use i would recommend:

1. use height units (this will scale appropriately to all screen sizes)
2. use a rectangle rather than a line
3. set the width and height of the rectangle separately. I see at the moment that you are using a variable line_polygon_pixels (perhaps fed in from a column in a spreadsheet). instead I would suggest having two columns line_width line_height start testing that using values like 0.05 for width and 0.2 for length (5% of screen height ant 20% respectively, this will make a horizontal line) from there you can adapt the values used for width and height appropriately for your experiment.

Hope this helps,
Becca

[ilkekav]

Hi, thank you. For some reason now cursor won’t move simultaneously and I am seeing a rectangle. Did I get that wrong?

Thanks!

[ilkekav]

I also changed the name for the size"currentline"(it was the random line length column in the spreadhsheet that will be shown in response trial) to "line_height "so code looks like this:

But now I get…: UnboundLocalError: local variable ‘line_height’ referenced before assignment

[ilkekav]

Hi, I created a new spreadsheet like this both for the display and the response trial, I also changed the orientation from 90 to nothing and entered the size the name of the colunns like this: [line_rect_len,line_rect_width] but still didn’t work. Do you have any idea why this is happening

? We don’t get errors. @wakecarter

[Becca]

Hi There,

Given the spreadsheet that you have you want to update your target_line component to look like the below

1. so that you are using both current_line_len and current_line_width to set he line.
2. set the line size every repeat
3. use height units not pixels in your spatial units.
   
   

I think the current reason your line is invisible is because your units are pixels and 0.0001 of a pixel is too small to present.