diff --git a/lightpreview/glview.cpp b/lightpreview/glview.cpp
index a26f4a72..3f9fee7d 100644
--- a/lightpreview/glview.cpp
+++ b/lightpreview/glview.cpp
@@ -78,9 +78,10 @@ out vec4 color;
 uniform sampler2D texture_sampler;
 uniform sampler2D lightmap_sampler;
 uniform float opacity;
+uniform bool lightmap_only;
 
 void main() {
-    vec3 texcolor = texture(texture_sampler, uv).rgb;
+    vec3 texcolor = lightmap_only ? vec3(0.5) : texture(texture_sampler, uv).rgb;
     vec3 lmcolor = texture(lightmap_sampler, lightmap_uv).rgb;
 
     // 2.0 for overbright
@@ -124,6 +125,7 @@ void GLView::initializeGL()
     m_program_texture_sampler_location = m_program->uniformLocation("texture_sampler");
     m_program_lightmap_sampler_location = m_program->uniformLocation("lightmap_sampler");
     m_program_opacity_location = m_program->uniformLocation("opacity");
+    m_program_lightmap_only_location = m_program->uniformLocation("lightmap_only");
     m_vao.create();
 
     glEnable(GL_DEPTH_TEST);
@@ -151,6 +153,7 @@ void GLView::paintGL()
     m_program->setUniformValue(m_program_texture_sampler_location, 0 /* texture unit */);
     m_program->setUniformValue(m_program_lightmap_sampler_location, 1 /* texture unit */);
     m_program->setUniformValue(m_program_opacity_location, 1.0f);
+    m_program->setUniformValue(m_program_lightmap_only_location, m_lighmapOnly);
 
     // opaque draws
     for (auto &draw : m_drawcalls) {
@@ -198,6 +201,12 @@ void GLView::setCamera(const qvec3d &origin, const qvec3d &fwd)
     m_cameraFwd = {(float)fwd[0], (float)fwd[1], (float)fwd[2]};
 }
 
+void GLView::setLighmapOnly(bool lighmapOnly)
+{
+    m_lighmapOnly = lighmapOnly;
+    update();
+}
+
 void GLView::renderBSP(const QString &file, const mbsp_t &bsp, const std::vector<entdict_t> &entities)
 {
     // FIXME: move to a lightpreview_settings
diff --git a/lightpreview/glview.h b/lightpreview/glview.h
index 3a8bb9ea..05c6855a 100644
--- a/lightpreview/glview.h
+++ b/lightpreview/glview.h
@@ -71,6 +71,9 @@ private:
         return v;
     }
 
+    // render options
+    bool m_lighmapOnly = false;
+
     QOpenGLVertexArrayObject m_vao;
     QOpenGLBuffer m_vbo;
     QOpenGLBuffer m_indexBuffer;
@@ -92,6 +95,7 @@ private:
     int m_program_texture_sampler_location = 0;
     int m_program_lightmap_sampler_location = 0;
     int m_program_opacity_location = 0;
+    int m_program_lightmap_only_location = 0;
 
 public:
     GLView(QWidget *parent = nullptr);
@@ -99,6 +103,7 @@ public:
 
     void renderBSP(const QString &file, const mbsp_t &bsp, const std::vector<entdict_t> &entities);
     void setCamera(const qvec3d &origin, const qvec3d &fwd);
+    void setLighmapOnly(bool lighmapOnly);
 
 protected:
     void initializeGL() override;
diff --git a/lightpreview/mainwindow.cpp b/lightpreview/mainwindow.cpp
index fa4a163f..593a766b 100644
--- a/lightpreview/mainwindow.cpp
+++ b/lightpreview/mainwindow.cpp
@@ -55,11 +55,13 @@ MainWindow::MainWindow(QWidget *parent)
     vis_options = new QLineEdit();
     light_options = new QLineEdit();
     auto *reload_button = new QPushButton(tr("Reload"));
+    auto *lightmap_only = new QCheckBox(tr("Lightmap Only"));
 
     formLayout->addRow(tr("qbsp"), qbsp_options);
     formLayout->addRow(vis_checkbox, vis_options);
     formLayout->addRow(tr("light"), light_options);
     formLayout->addRow(reload_button);
+    formLayout->addRow(lightmap_only);
 
     auto *form = new QWidget();
     form->setLayout(formLayout);
@@ -83,6 +85,8 @@ MainWindow::MainWindow(QWidget *parent)
     // setup event handlers
 
     connect(reload_button, &QAbstractButton::clicked, this, &MainWindow::reload);
+    connect(
+        lightmap_only, &QCheckBox::stateChanged, this, [&]() { glView->setLighmapOnly(lightmap_only->isChecked()); });
 }
 
 MainWindow::~MainWindow() { }
@@ -254,24 +258,19 @@ void MainWindow::loadFileInternal(const QString &file, bool is_reload)
 
     glView->renderBSP(file, bsp, ents);
 
-    if (!is_reload)
-    {
-        for (auto &ent : ents)
-        {
-            if (ent.get("classname") == "info_player_start")
-            {
+    if (!is_reload) {
+        for (auto &ent : ents) {
+            if (ent.get("classname") == "info_player_start") {
                 qvec3d origin;
                 ent.get_vector("origin", origin);
 
-                qvec3d angles {};
+                qvec3d angles{};
 
-                if (ent.has("angles"))
-                {
+                if (ent.has("angles")) {
                     ent.get_vector("angles", angles);
-                    angles = { angles[1], -angles[0], angles[2] }; // -pitch yaw roll -> yaw pitch roll
-                }
-                else if (ent.has("angle"))
-                    angles = { ent.get_float("angle"), 0, 0 };
+                    angles = {angles[1], -angles[0], angles[2]}; // -pitch yaw roll -> yaw pitch roll
+                } else if (ent.has("angle"))
+                    angles = {ent.get_float("angle"), 0, 0};
                 else if (ent.has("mangle"))
                     ent.get_vector("mangle", angles);