# A few questions

**URL:** <https://forum.generic-mapping-tools.org/t/a-few-questions/3400>\
**Category:** Q&A\
**Created:** [November 1, 2022, 11:17pm UTC](https://forum.generic-mapping-tools.org/t/a-few-questions/3400 "2022-11-01T23:17:55Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![PlanetGus](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/planetgus/32/303_2.png) [@PlanetGus](https://forum.generic-mapping-tools.org/u/PlanetGus)\
**Post date:** [November 1, 2022, 11:17pm UTC](https://forum.generic-mapping-tools.org/t/a-few-questions/3400/1 "2022-11-01T23:17:56Z")

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Hello GMT gurus !

1. 

Is it just me or transparency doesn’t work with `grdview` ?  
I’m trying with `-Qc`, `-Qi`, `-Qs` … to no avail  
Is there another way to plot structures in 3D ?

1. 

We have the so-called “vertical” scalebar with cartesian plots (using `-L[...]+v`) but we don’t have the option for geographical maps.  
I get how irrelevant it can get using some projections and/or extended maps. But it’s not always the case right?  
I guess a workaround would be to overlay a simple rotated basemap but that’s overkill …

1. 

`mapproject` takes perspective (`-p`) as input, but when I try to get the height of my plot, the result stays the same with or without `-p`

1. 

Talking about perspective … see [github issue](https://github.com/GenericMappingTools/gmt/issues/7066)

1. 

What does the `-T` do in `grdtrack` ?